Glossary of terms

Technical terms simply explained

“c” internationally used abbreviation for “color” in the sense of the number of colors that can be printed on a printing press in one run, e.b. 4c (four-color printing), 6c (4 process colors + 2 special colors), 4/4c (4 colors each in recto / verso printing, or top and bottom side of the web, or 4-color duplex digital printing).

“C” internationally used abbreviation for absorptive primary color cyan blue, thus also for the technical printing process color cyan. In large-format inkjet printing systems, the abbreviation Cc means the support of cyan with “light cyan” to enlarge the color space.

calibration calibrage resetting of the target values of a device, either according to manufacturer’s specifications or according to a standard. In color management, calibration with reproducible basic settings is a precondition for successful characterization in color space and the subsequent application validity of the created ICC profiles. In the hardware calibration of monitors, the setting of the target value and characterization are combined into one step.

camouflage color couleur de camouflage color shade or halftone-like mixture of several color shades which allows the color surface to merge visually with the environment.

CAUS Color Association of the United States.

CCR, complementary color reduction réduction des couleurs complémentaires process of achromatic composition: restriction of under color removal UCR and gray component replacement GCR on the blend colors R, G and B, which are complementary to C, M and Y; reduction of two chromatic colors each in the blackish drift range of their complementary colors.

ceramic inks and toners encre céramique printing inks and color agents which are printed either directly (screen, tampo printing) onto a ceramic surface (tiles, porcelain) or indirectly (screen, sheet-fed gravure printing) onto a transfer paper. With transfer paper, the reverse order of the covering ink films must be taken into account. In general, the sub-sequent burning-in of the glaze leads to a strong color drift (burning-in drift), which can only be predicted with costly ICC profiles.

charge-coupled device dispositif à couplage/transfert de charge device consisting of light sensitive semiconductor diodes arranged line-wise or matrix-wise; application: scanners, video and color measuring cameras; replaced by CMOS sensors on account of the slow charge displacement and susceptibility to overexposure in digital photography and spectrophotometry.

chroma chroma synonym for chromaticness; original designation for the “value C” in the Munsell color ordering system. Chroma Cosmos 5000 Japanese color ordering system
comprising 5000 color specimens, according to the Munsell principle.

chroma[ticness] chroma coordinate C* in the intuitive L*C*hab coordinate system (brightness/chromaticness/hue angle) of the CIELAB color space; difference between a hue and its equally bright achromatic stage; not to be confused with saturation S* = C*/ L*.

chromatic chromatique the technically correct term for “colored” (coloré) opposite: achromatic.

chromatic aberration aberration chromatique an aberration in optical systems in which color fringes are formed on the edges of objects in the image.

chromatic adaptation adaptation chromatique at a color temperature deviating from 5000 K, a c.a. is automatically activated in monitor hardware calibration and other color
management programs, e.g. the simple Bradford and von Kries transformations or the more complex CAT02 adaptation (CIECAM02).

chromatic/regular color separation composition chromatique conventional CMYK color separation process in which all four colors are involved in the representation of each chromaticity coordinate in all tone areas, resulting in high overall total ink coverage (up to 400%) and thus drying problems; K is only used to support the dark image parts (“skeleton black”) because the chromatic printing inks provide only inadequate details when C+M+Y are printed together. chromatic/regular color separation modifications; slight and strong under color removal (UCR), possibly combined with gray component replacement (GCR).

chromatic dispersion dispersion chromatique dispersion of a light ray into its spectral components through diffraction on a lattice or through refraction at the boundary surfaces as it passes through a prism; application: monochromator in spectral densitometers in order to be able to isolate the wavelengths contributing to the color stimulus.

chromatic stimulus simulation simulation des stimuli chromatiques experimental arrangement (light spots, gyratory color mixer) with which primary colors can be proportionately changed and additively blended in order to test a person’s color sense (e.g. for permits for certain professions such as printer and graphic designer, but also architect, bus driver, electrician, textile and fur good quality inspector).

chromaticity chromaticité family of color stimuli which differ only through their brightness, i.e. hue and chromaticness remain constant. In a cut through a color space parallel to the lightness axis the colors of one chromaticity always show the same distance from the lightness axis at each lightness level and thus always the same chromaticity coordinates.

chromaticity chart/diagram diagramme de chromaticité two-dimensional section through a color solid at a level of equal brightness. Only the hue parameters (CIExyY chromaticity chart) or chrominances (a*;b* chromaticity chart from CIELAB) are shown in this view.

chromaticity coordinates/locus [Pl. loci] coordonnées de chromaticité description of the colorimetric properties of a printing ink with the help of colorimetric values (vector
coordinates in the color space).

chromaticity shift virage changes in the chromaticity coordinates in the course of the drying of printing ink; while wet and dry color densities differ due to the diminishing wet gloss alone, with wet and dry colorimetric values the influence of the oxidation or wetting reactions or evaporation and penetration, which are characterized by changes in the solids concentration or structure, have to be added.

chromaticity/hue shift décalage de la couleur phenomenon consisting in the fact that when one of the three color attributes hue, brightness or chromaticness changes, chromaticity also changes. There is only one case in which chromaticity does not change, namely when the change in brightness is not due to a change in hue and/or chromaticness. Application: color selection tool in Adobe Creative Suite.

chrominance chrominance a chromaticity coordinate in opponent-color luminance-chrominance color spaces (CIELAB, CIELUV, YcrCb, YIQ etc.), described by its position in relation to the red-green axis (a*, a’, Cr, I) and the blue-yellow axis (b*, b’, Cb, Q). This coordinate model of color components independent of the lightness level (luminance L*, L’, Y) assumes that a color cannot be tinted red and green, or blue and yellow, at the same time.

chromogenic inks encres chromogènes printing inks with pigments which change their color temporarily or irreversibly in the event of external physical effects; c.i.s offer a great potential in packaging printing (transportation imitation-proof); most c.i.s are available for flexo printing, only from a few manufacturers for offset printing.

CIE chromaticity chart/diagram, “color triangle”, “horseshoe” diagramme (chromaticité) CIE, tableau normalisé/ triangle des couleurs, « fer à cheval » CIExyY(1931) chromaticity chart originating from the projection of the CIE colorimetric system CIEXYZ(1931).

CIE chromaticity coordinates coordonnées trichromatiques CIE the coordinates of the CIE chromaticity chart: x = X / (X + Y + Z), y = Y / (X + Y + Z), z = Z / (X + Y + Z).
Since x + y + z = 1, i.e. x and y already unequivocally describe chromaticity coordinates, the specification of z is dispensed with; instead, the standard color value Y (xyY) is specified as luminance factor A for the 2° standard observer.

CIE Commission International de l’Éclairage International Commission on Illumination; Vienna (Austria)-based commission for issuing photometric and colorimetric recommendations on which the relevant ISO standards for many different fields of
application are based, e.g. standard illuminants (D50, D65, A), standard observers (2°, 10°) and color spaces (CIEXYZ, CIELAB, CILUV) including color difference formulae. As in
the ISO, there are also Divisions here with Technical Committees (CIE TC) which prepare sector-specific standards. The most important Divisions for color communication are
1 “Vision & Color” (color vision, color difference formulae, light measuring technology, illuminants) and 8 “Image Technology”

CIE spectral distribution coefficients coefficients colorimétriques CIE see CIE tristimulus curves/functions

CIE tristimulus curves/functions fonctions trichromatiques CIE continuous function (for 2° and 10°) in the virtual CIE colorimetric system CIEXYZ, 1931 referring to the wavelength λ (at 5 nm intervals) calculated as a standardization of the real fundamental stimulus system PDT. The three function terms can be regarded as the CIE tristimulus values X, Y, Z in CIEXYZ.

CIE tristimulus values composantes trichromatiques CIE color values of the CIE colorimetric system CIEXYZ; standardized representation of the cone sensitivities X (red), Y (green) and Z (blue) whereby, through definition of the luminance factors (brightness factors) LX = 0, LY = 1 and LZ = 0, the CIE tristimulus value Y is also understood as brightness and as luminance factor A in the 2° CIE colorimetric system; see also weighted ordinates principle.

CIE94, CIE(1994) modified CIELAB color difference formula, see inside of back cover

CIECAM02, CIE colour appearance model 2002 modèle d’apparence de la couleur CIE 2002 most-used color appearance model, component of among other things Apple Color-Sync and MS WCS and of the leading color management, monitor calibration and soft copy proof applications. After the actual color values of the color stimulus (whose appearance is to be simulated), of the illuminant (of the white point to be adapted) and of the environment as well as of the ambient lightness value have been entered, it calculates the following intuitive color attributes (perception parameters): hue H, lightness J, brightness Q, chroma C, colorfulness M, saturation S and chrominances ac, bc. As algorithms it offers the chromatic adaptation CIECAT02, whose subsequent adaptation (nonlinear color space compression) and the resulting changes in the perception parameters.

, CIE chromatic adaptation transform 2002 transformation d’adaption chromatique CIE 2002 see CIECAM02

CIELAB(1976), CIE L*a*b* device-independent color space defined for the evaluation of small color differences, with perceptually equidistant structure, defined in 1976 by the CIE together with the trivial color difference formula ΔE*ab (Delta E = Euclidian distance in space) on the basis of the Hunter-Lab color space (1948). The luminance axis L* stands vertically on the achromatic point of the a*;b* chromaticity chart and forms a rotational solid. Brightness L*, red-green chrominance a* and yellow-blue chrominance b* are therefore cylinder coordinates that are supplemented by the intuitive CIELCH interpretation – see inside of back cover. CIELAB is based on the colorimetric values X and Y of the CIE colorimetric system CIEXYZ (1931). Although the color difference formula was improved several times – see CMC (CIELCH84), CIE94, CIEDE2000 inside of back cover – the 1976 CIELAB definitions still form the basis for all international image data exchange standards (printing process in accordance with ISO 12647 incl. process standard offset printing, ICC profile linking color space beside CIEXYZ) and various color ordering system (e.g. RAL). The suggestions for improvement of the CIELAB color model itself – CIELAB-ND(1978), LABHNU(1979- 1/-2), LABJNDS(1984) and DIN99 (DIN 6176:2001-03) by Klaus Richter (BAM) – did not gain acceptance either.

CIELCH(1976), CIE L*C*h intuitive interpretation of the CIELAB color space with its own derived coordinates – see inside of back cover; intuitive color attributes here are L* = luminance, C* = chromaticness and H* hue or h° hue angle.

CIELUV(1976), CIE L*u*v* device independent color space defined for the assessment of small color differences, issued by the CIE in 1976 together with the trivial color difference formula

color graphic design, coloring coloration, mise en couleurs artistic-design-based selection and placing of hues.

(color graphics) display moniteur visual inspection device on the user interfaces of graphic workplaces and soft copy proof-to-press solutions. An LCD display consists of an active matrix panel, backlighting (cold white fluorescent lamps or white light LEDs), housing with electronic control unit (including its own graphics card with calibration-capable CLUT) and a hood. The pixels with their subpixels R, G, B work according to the additive color blend principle. Further parameters: see NEC.

color guide, color swatch (book) nuancier color selection system for designing printed matter; color sample on different substrates, e.g. uncoated paper, coated paper, newspaper or films; examples: HKS, Pantone.

color imposition emplacement des couleurs in color printing, the distribution of the  separation colors of a print job between the available printing units, in sheet-fed offset for example on a six-color machine 2/4 or 6/0, in newspaper printing for example in four-high units or satellite units 4/4, 2/4, 3/3 etc.

Color Index, C.I. international name classification of color agents introduced in 1925; the name is composed of “C.I.”, “Class” (dyes, pigments), “Color name” (chromatic color from the color circle or a tertiary tone, achromatic color, metallic), “Type number” (consecutive index number for the various chemical substance and application types, e.g. acid/alkaline substances, diazo dyes, color couplers, food colors, optical brighteners, bleaching agents), “Constitution number” (consecutive chemical  modification number), e.g. C.I. Pigment Blue 15:1.

color indexing indexation des couleurs processing of true color files (8 bpp) in image processing programs which only accept considerably lower pixel depths (a total of 8 bits); in this case a color palette which has been reduced to 256 colors is invoked, and the 16.7 million true color hues are represented with losses on this palette.

color intensity intensité measure for the intensity of a color perception. Color intensity increases with the chromaticness of the color and decreases with its brightness; dyeing products manufactured with the same color depth are only apparently manufactured with the same concentration of equally strong color agents (cf. color strength).

color job travail en couleur print job requiring a color workflow.

color layer couche de couleur unlike saving in color channels (e.g. RGB in one level), some file formats (but not TIFF or JPEG) can also save each of the color channels in individual levels, which makes it possible to simulate CMYK color separations,for example.

color library bibliothèque de couleurs systematic collection of spot color data records in the form of a color palette (indexed colors), a color database (spectral luminance factors) or a digital color fan (spectral data, CIELAB). Pantone makes its color fans and palettes available as plug-ins. Techkon provides its spectral densitometer with HKS color fans; the user has the option of creating his own color libraries with the measuring unit and to use the SpectroConnect software to export them and import them into other devices. Basically, a collection of “named color profiles” for special colors also represents a color library.

color LUT color look-up table, color setting table table de correspondance des couleurs entirety of the color values created in image and graphic data exchange formats for assignment to grayscales. Examples: color LUTs in graphics programs, tables anchored in the graphics card for monitor calibration, transformation rules in ICC profiles.

color management gestion des couleurs entirety of all workflow scenarios that assure desired, exactly predictable color rendering in all imaging processes and media. As standard, color management is based on the ICC profile specification, which numerous software applications more or less conform to. Thanks to such solution providers as basICColor, who do not stick strictly to the ICC specifications, but also supply tools which compensate for the conformity deficits of important publishing programs and close certain workflow gaps, color management has managed to develop into a comfortable and reliable technology for color quality assurance.

color management system, CMS système de gestion des couleurs technological entirety of operating system architecture, ICC profiles and ICC-conform software which, with the help of color measuring technology, can create individual device profiles and suitably link these, from input to output, with the color documents to be published. A CMS ensures color consistency in a digital workflow and in each phase should make sure that the output target is simulated exactly in terms of color and reproducibility at all times.

color match 1) échantillonnage visual comparison between color pairs or reference and sample. 2) ajustement step by step approximation of a sample (printed copy, monitor view) to the reference (media, proof etc.) by means of visual or technical comparison.

color-matching booth/cabinet/unit cabine de contrôle, cabine à lumière desktop testing device offering standardized observation conditions (neutral gray interior walls, brightness 2000 lx, no influence of ambient light) for color matching; depending on the industry, but also to test metamerism effects, the following illuminants can usually be switched on: CIE A, CIE D50, CIE D65, department store light TL84, UV;

color matching module module de gestion de couleur see CMM

color measurement/measuring, colorimetry colorimétrie process for non-destructive materials testing to determine the spectral properties of a surface (ISO 13655:) or of a light source (DIN 5033-8) or of the color rendering characteristics of a device (ISO 12641/12642); carried out with spectrophotometers or spectrodensitometers which can calculate all colorimetric values on the basis of the spectral luminance factor. Before the beginning of measuring, the measuring device must be calibrated to an absolute white standard, also supplied.

Color Mixer mixeur couleurs 1) digital color palette and color selection tool (numerical input, intuitive slide control) in  various publishing programs, including Adobe Creative  Suite. 2) Tables by IWA to predict the combined printing of color shades with graduated  half-tone values. 3) Color circle to demonstrate additive color mixing.

color ordering system nuancier, système de classification des couleurs usually perceptually equidistant color specimen plates in which the individual hues are ordered according to intuitive attributes: proceeding from the lightness axis with growing chromaticness, each plate corresponds to a chromaticity type or hue family. Examples: Munsell Book of Colors, Ostwald’s double cone.

color perception/sensation perception chromatique the effect developing in the brain of a physical color stimulus (light), which is perceived by the eye as a chromatic stimulus.

color pigment pigment coloré designation for chromatic pigments for ceramic products.

color printing system système d’impression en couleur all printing presses, office printers and digital copiers that print more than the color black.

color reciping software logiciel de formulation des encres computer program which uses absorption dispersion equations to mix special colors from a range of basic colorsincl. ink residues (residual ink recycling) or a system of concentrates, for example X-Rite Ink Formulation and Connex  Alwin II (PV).

color reduction, ink weakening allongement dilution of the printing ink with the solvent it is based on or with a blended substance.

color reference échantillon de référence each template that can be copied in color and is therefore compared with a current sample.

(color-to-)color register repérage des couleurs register accuracy between the print formes of the individual process colors in multicolor printing. Color register control duringproduction printing is effected either at the image edges or on control elements that are also printed (register crosses), either visually with a magnifying glass or metrologically with a video camera which triggers the adjustment of the plate cylinder inthe printing press as a component of a control cycle.

color rendering index, CRI indice de rendu des couleurs colorimetric quality of a light source for suitability for adjustment or color matching; measure for the accuracy of a color impression obtained by the illumination of a chromatic object (test colors according to DIN 6169-2:1976) compared to a D50 reference light source: Ra = 100 – 4.6 × ΔE*ab; for color-matching booths and control station desks, an index > 90 is required;the LED technology of Just Normlicht reaches approx. 99.

color rendering rendu des couleurs quality of the color appearance with which a color image is represented in the target medium, or is simulated first on a monitor or in the digital proof.

color separation file/print sélection couleurs imaging file or its partial printing result for each of the printing inks involved in the print process.

color separation séparation/sélection des couleurs production of color separation files/prints for multicolor printing; the color separation files/prints of the process colors CMYK must have different screen angles to prevent a moiré effect.

color solid solide des couleurs geometrical representation of a color model, e.g. sphere (Runge), double cone (Ostwald), rhombododecahedron (Küppers) or irregular structures (Rösch, CIELAB color space).

color space espace chromatique/colorimétrique three-dimensional representation and relation model of chromaticity coordinates. A distinction is made between device-dependent color spaces (RGB, CMYK) in accordance with the technical color channels, and device-independent color spaces (CIEXYZ, CIELAB), which represent the entire perceptible color space.

color space models and derivates modèles colorimétriques et espaces colorimétriques dérivés to extend the understanding of a color space, which is actually also a color space model, so-called derived color spaces must also be included in this discussion – specially prepared systems which can be traced back to the analysis color space CIEXYZ (deviceindependent) and the analysis and synthesis color space RGB (device-dependent) or the synthesis color space CMYK (device-dependent). Color spaces derived from CIEXYZ are CIExyY, CIELUV, CIELAB, and from these in turn CIELCH, HLS, HSV, HSB. R’G’B’J’ (elementary hues) and Kodak YCC are derived from RGB. CMYK  and K (achromatic) are derived from CMY.

color (space) transformation transformation de l’espace chromatique see gamut mapping

color specimen book, spot-color sample book nuancier, atlas des couleurs collection of samples, printed or as PDF files, of printable chromaticity coordinates (e.g. on account of the restricted color space in newspaper printing or to extend the color space of hifi-color scales) and pigment effects.

color stimulus [Pl. stimuli] stimulus de couleur 1) physical identification of the light radiation which, through direct stimulation of the cones (retinal receptors) causes a perception which can be felt as color. The color stimulus can come from a primary radiator (light source) as well as from a secondary radiator (remitting surface). 2) identification in terms of value of chromaticity coordinates in the color space with the help of a vector pointing from the coordinate origin 0 to the chromaticity coordinates (localized vector). The vector is formed through the addition of for example vectors rR, gG, bB. A distinction is made between primary stimuli R, G, B (additive color mixture), basic stimuli P, D, T (description of daytime vision, adaptation and color vision deficiency by means of the 3 cone types PDT and recently LMS) and virtual standard stimuli X, Y, Z (CIEXYZ, description of all colorimetric phenomena).

color stimulus function courbe spectrale d’un stimulus de couleur mathematical description of the color stimulus with curves for the weakening of the luminous flux for wavelength intervals of 5 to 20 mm. Under a certain illuminant, the color stimulus function (physical “transmitter”) creates concrete standard color values with the standard spectral value functions (physiological “receiver”).

color strength pouvoir/puissance colorante measure for the ability of a color agent to have a coloring effect on other materials; measurable as absorptance depending on the concentration of the coloring agent in the material to be dyed.

color substitution technique de fausse couleur Process for increasing contrast during visual image assessment. Pure grayscales can be assigned arbitrarily selected hues withadditional information (infrared: temperatures) with infrared camera images or the hardly perceptible brightness levels within one chromaticity level (e.g. leaf green hues in satellite  photos to analyze forest dieback).

color synthesis synthèse des couleurs combined print of the color separation files/prints

color system système colorimétrique system for arranging the color stimuli, it always represents only the basic principle of a color mixture and not its technical implementation.

color table table des couleurs see CLUT

color temperature température de couleur measure Tx in Kelvin [K] or Mired [M] (M = 1000000/K) for the color im – pression of a light source compared to the luminescent color which the ideal “blackbody” (Planck radiator) gives off at a certain temperature. Three cases must be distinguished:
1) the Planckian color temperature PCT TP (température de couleur de Planck) itself, which shows this ideal body with the full  absorption of incident heat radiation, whereby it passes through the merging stadia of  red heat, yellow heat, white heat and blue heat; this constant passage is represented as the Planck curve in x;y-, u*;v* and a*;b* chromaticity charts; for each TP a concrete spectral radiation distribution can be determined, characterized by a continuous (gap-free) and constant (peak-free) curve characteristic; TP corresponds to the true glow temperature T.
2) the color temperature of relative spectral power distribution (DCT) TD (température de couleur de la répartition spectrale relative d’énergie) of a glowing technical radiator (e.g. light bulb) which, while having the same chromaticity as the Planck radiator, also has a continuous spectral radiation distribution curve; TD is lower than the true glow temperature T of this technical radiator.
3) the nearest or correlated color temperature (CCT) Tn, Tc (température de couleur de corrélée) of a random light source (e.g. sun, fluorescent lamp, quartz lamp, LEDs), which agrees approximately with the Planck radiator only in the light coloring(that is, whose chromaticity approaches the Planck curve), but which has to show neither a continuous nor constant radiation distribution curve – see Tables C-2 “Correlated color temperature” on page 32; Tn,c can be very much lower than the true temperature T of this light  source. In the simulation of the standard illuminant D50 in the media industry, the color temperature Tn = 5003 K = 199.9M is less authoritative than the color rendering index on account of the approximation to the desired relative spectral radiation distribution (metamerism!).

color transformation transformation chromatique see gamut mapping

color transparency, tranny, chrome, color slide diapositive, transparent analog color image original; in the age of digital photography, exists only as archive material.

color triangle triangle chromatique see CIE chromaticity chart

color tune ambiance color stimulus which is determined primarily by the illuminant and secondly by the dominant remission symptoms and which “overlays” other possible color stimuli; e.g. the light from light bulbs conveys a warm-reddish color tune.

color TV télévision en couleur image transmission according to different color standards and color signal descriptions; for all standards (NTSC, PAL, SECAM and HD successor systems) the color space YIQ applies, with luminance Y, the I-signal chrominance and the Q-signal chrominance  see there.

color vignette dégradé continuous, gradual transition from one color shade to another.

color vision deficiency, color-blindness défaut de vision des couleurs, achromasie deviation from normal color vision (accurate color daytime vision) among approx. 5% of human beings on account of the differing functioning (anomaly: color pair metamerism) or of the failure (anopia: color pair confusion) of one (dichromatopsia) or two (monochromasy) of the three types of retinal cones. Persons with color vision deficiency are unfit for occupations in which colors play an important role; the required determination of normal vision is effected using the Stilling-Hertel test, and of the type of color vision deficiency with Ishihara plates.

color vision vision des couleurs brightness-adapted vision (daytime vision) with the 3 types of retinal cone.

color wheel/circle, hue circuit cercle chromatique systematic arrangement of hues of maximum chromaticness as the starting point for a color ordering system. The arrangement is effected either clockwise or counterclockwise, but always in accordance with the wavelengths in the light spectrum, whereby the beginning (blue-violet) and end (red-orange) of the visible spectral ranges are bridged by a purple area. Depending on the task, the hues are arranged as perceptually equidistant (Munsell, CIELAB) or with a complementary opposite (Ostwald system).

colorant mixing mélange des colorants creation of dyes and pigments according to color references.

colorant, color agent matière colorante materials that change the colors of objects and substances; there is a rough distinction between dyes and pigments (color index) as well as coverage capacity, trueness, color strength or scatter capability (DIN 55943), white, chromatic, black, gloss or luminescent colorants (DIN 55944), natural and synthetic colorants (DIN 55944).

colored coloré obsolete term for chromatic; opposite: colorless, achromatic.

colorfulness chromie one of the three intuitive attributes of luminescent colors: brightness–colorfulness–hue (clarté – chromie – teinte).

colorimeter colorimètre 1) Triple-range measuring device, i.e. a colorimetric measuring instrument which works with a measuring filter characteristic which corresponds to the three standard spectral value curves x(λ), y(λ), z(λ), whereby x(λ) usually has to be implemented with 2 filters. Ideal device class for measuring monitors, e.g. the hardware calibration and validation of wide-gamut monitors, whereby the basICColor Discus is the only colorimeter that can also perform tele-measurements from the typical practical viewing distance. The suitability for monitors (self-luminant bodies) results from the continuous coverage of the spectrum thanks to the filter and from the noise-free measuring of dark luminescent colors.
2) Measuring device for determining the color intensity of liquids as a measure of the concentration of a chemical solution.
3) Measuring device for the astronomical determination and classification of self-luminant celestial bodies in temperature-
volume classes, e.g. “yellow giants”, “blue dwarfs”.

color(imetric) measuring instruments/devices appareils de mesure de la couleur device classes of different efficiency levels and aptness: l-a-d meter (colorimeter), spectrophotometer, spectrodensitometer and colorimetric measuring camera. On the basis of a measurement over the entire visible spectrum, a spectrodensitometer can evaluate the most varied  quality parameters.

colorimetric parameters, colorimetry of sthparamètres colorimétriques see colorimetric values

colorimetric toning tonalité colorimétrique
1) relationship between chromaticness and brightness in the CIELAB system.
2) relative colorimetric toning; method according to which, instead of a color densitometer the color effect of a screened tone value is evaluated with a spectrophotometer; is no longer used in practice, except for the DFTA Dot Gagin Compensation Tool for flexo printing.

colorimetric values/coordinates coordonnées colorimétriques mathematical values for the description of chromaticity coordinates; the parameters used for this depend on the selection of the color space model, e.g. x and y in the CIExyY(1931) color space or L*, a* and b* in the CIELAB(1976) color space. The values apply only for the illuminant and the standard observer, which must also be specified, e.g. D50/2°.

colorimetry métrique des couleurs mathematical description of the distance relationships in the color space; low colorimetry describes the phenomenon of color vision and defines standard light sources (standard illuminants), higher colorimetry is dedicated to the evaluation of color differences (color difference formulae). In the final resort, the comparability of color perceptions is based on the comparability of chromatic stimuli, which as localized vectors in the color space offer a figure or value-based description of color perceptions, i.e. are in a position to define distances between two points (namely coordinate zero point and a chromaticity coordinate) and a color measurement can only be effected on the basis of a distance definition and general comparability

colorness dominante in the sense of opponent color theory, orientation with respect to the red-green and the yellow-blue axes e.g. in CIELAB, that is, the redness, greenness, blueness
and yellowness.

Coloroid système chromatique Coloroïd aesthetically equidistant color space, which was created in 1962 by the Hungarian colorimetrician A. Nemcsics for architectural design (1600 color samples) on the basis of CIEXYZ. Its structure is similar to that of the CIELCH interpretation: hue A (“árnyalat”, color circle sectors 10 to 76), brightness V (“világosság”, 0 = black, 100 = white) and chromatic share T (“tarkaság”, 0 = achromatic, 100 = maximum chromatic) – syntax A-T-V. Conversion to CIELAB is possible via XYZ.

compact source iodide lamp lampe CSI compact metal
halogenid lamp, which is used for analog printing form copy because of its UV component.

complementary colors couleurs complémentaires pairs of colors which form white when additively mixed in the same proportions. In classical color densitometers, the measuring filters are complementary to the chromatic process printing inks (red filter for cyan, green filter for magenta, blue filter for yellow) in order to be able to record the highest absorption ranges for each of the printing inks.

composing assemblage
1) in digital image processing and graphics creation, the creation of motifs from different images in grouped image files or in a new image file, with artificial light and shadow effects being used.
2) Text-image integration. In both scenarios, the uniform color rendering quality of the individual elements is a challenge.

composite file fichier composite file form in which the color separation has already taken place, but the color separation files are still together in one single file for illustration and handling reasons, that is, the division into individual color   separation files has not yet taken place, e.g. Composite PDF.

cones, uvulas cônes (de la rétine) retinal receptors responsible for daytime vision and thus for color vision

conglomerates conglomérats intended agglomeration of pigment particles in wide gamut inks, in order to achieve higher color densities through maximum pigment concentration and color strength.

consistency, match concordance result of a color comparison without recognizable or measurable deviation.

continuous tone, CT ton continu designation for continuous tone value transitions, like those in photographic originals; the English word “halftone”, on the other hand, is used for halftone images.

contract color-proofed épreuve couleur contractuelle quality of a digital proof or press proof whose printed image agrees with the subsequent production run image in color rendering, whereby compliance with the relevant tolerances (color and chromaticness distances in the evaluation of a control element, e.g. media wedge) is to be documented so that it is forgery-proof.

corporate/CI color couleur spéciale color shade that is communicated as part of the corporate identity in logos, labels and color surfaces and which is technically implemented either as a spot color, a special color or CMYK separation; can be protected as a color trade mark or patent; examples of color ordering systems: ADAC: “Rape yellow” RAL 1021; Aral: blue background HKS 47; Deutsche Telekom: “Telemagenta” Pantone Rhodamine Red U; Red Bull drink can: “ultramarine” Pantone 2747 C on “silver” Pantone 877 C; Ferrari red: hexadecimal code FF1C00 or paint code 35478; examples of patented color trade marks: Beiersdorf: Nivea blue; Coca-Cola: CC red, CC light red; Kraft Foods: Milka lilac.

Cromalin Brand of DuPont de Nemours (USA); in the era of analog proofs, became their synonym. CRT display, cathode ray tube display moniteur CRT, écran à tube cathodique out-of-date cathode ray tube design for monitors and television sets; advantages: surface homogeneity, viewing angle-independent color rendering, high resolution quality, slow ageing; disadvantages: space requirements   weight, electricity consumption, susceptibility to repairs. CT ton continu internationally used abbreviation for half-tone originals (color transparencies, photo prints, digital photos), as distinguished from HT (halftone) and LW (linework). CxF, Color Exchange Format ASCII/XML-based container created by GretagMacbeth and further developed by X-Rite for the exchange of device-dependent and device-independent color spaces, color physics (color values incl. spectra, gloss, thickness, transparency), illuminants and color tables (libraries, palettes); criticism: 1. submitted to ISO TC 130 as standard proposal, although still based on ANSI CGATS.17 and not ISO 28178:2009; 2. according to American measuring philosophy, no white paper balance provided for; 3. Scheme published, but in the event of SDK use, blocking period for rival products.