The Coloroid Color System is a

color space A color space is a specific organization of colors. In combination with color profiling supported by various physical devices, it supports reproducible representations of colorwhether such representation entails an analog or a digital represent ...

developed between 1962 and 1980 by Prof.

Antal Nemcsics Antal may refer to: * Andal, 8th-century poet saint of South India * Antal (given name) * Antal (surname) * 6717 Antal, a minor planet See also * Andal (disambiguation) Andal was a poet-saint of South India. Andal may also refer to: * Andal, ...

at the

Budapest University of Technology and Economics The Budapest University of Technology and Economics ( hu, Budapesti Műszaki és Gazdaságtudományi Egyetem or in short ), official abbreviation BME, is the most significant university of technology in Hungary and is considered the world's oldes ...

for use by "architects and visual constructors". Since August 2000, the Coloroid has been registered as Hungarian Standard MSZ 7300. Like the

OSA-UCS In colorimetry the OSA-UCS (Optical Society of America Uniform Color Space) is a color space first published in 1947 and developed by the Optical Society of America’s Committee on Uniform Color Scales. Previously created color order systems, such ...

and

Munsell Munsell may refer to: * Albert Henry Munsell (1858–1918), American painter, teacher of art, and the inventor of the Munsell color system * Harvey M. Munsell, American soldier in the Civil War. *Munsell Color Company *Munsell color system In c ...

systems, the Coloroid attempts to model a

perceptually uniform In color science, color difference or color distance is the separation between two colors. This metric allows quantified examination of a notion that formerly could only be described with adjectives. Quantification of these properties is of great ...

color space or UCS. However, the UCS standard applied in the Coloroid system is equal appearing increments in color when the entire range of colors is presented to the viewer, in contrast to the standard of equal "just noticeable" or small color differences between pairs of similar colors presented in isolation. Colors in the Coloroid color space are fundamentally specified according to the perceptual attributes of "luminosity" (

luminance Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls withi ...

factor, V), "saturation" (

excitation purity Excitation, excite, exciting, or excitement may refer to: * Excitation (magnetic), provided with an electrical generator or alternator * Excite Ballpark, located in San Jose, California * Excite (web portal), web portal owned by IAC * Electron exc ...

, T) and

hue In color theory, hue is one of the main properties (called Color appearance model#Color appearance parameters, color appearance parameters) of a color, defined technically in the CIECAM02 model as "the degree to which a Stimulus (physiology ...

(the matching or dominant spectral wavelength, A). The VAT components are used to define a cylindrical color geometry, with V as the achromatic vertical axis (lightness or brightness), T as the horizontal distance from the achromatic axis (chroma), and A as the hue angle around the hue circle. The circumferential limits of this cylinder are defined by the spectrum locus, or colors as they appear in a single wavelength of light (or a mixture of single "violet" and "red" wavelengths); this ambit varies vertically in V around the hue circle, showing whether the relative luminance or brightness of each wavelength is high (yellow hue) or low (violet blue hue). This defines the outer perceptual limits of the color space. Within this is the smaller perceptual volume defined by the limit of colors it is possible to reproduce with physical media (material colors). Here the VAT perceptual attributes can be approximately matched using the three stimulus or material color components of pure hue or pure colorant (''p''), white colorant (''w'') and black colorant (''s'') in relative proportions whose sum must always equal 1. (Implicitly, ''p'' may be any matching single "spot" colorant or matching mixture of two "primary" colorants.) The Coloroid technical documentation defines the conceptual equations necessary to transform the Coloroid perceptual components VAT into the corresponding stimulus components, using the

CIE XYZ The CIE 1931 color spaces are the first defined quantitative links between distributions of wavelengths in the electromagnetic visible spectrum, and physiologically perceived colors in human color vision. The mathematical relationships that defin ...

1931 color-matching functions with the D65 CIE illuminant. Hues are identified according to the hue angle ψ, measured on the

CIE 1931 The CIE 1931 color spaces are the first defined quantitative links between distributions of wavelengths in the electromagnetic visible spectrum, and physiologically perceived colors in human color vision. The mathematical relationships that defin ...

xy chromaticity plane. These stimulus attributes in turn must be standardized or gamut mapped into a specific colorant system or color reproduction technology in order to reproduce the Coloroid color space as physical color exemplars or a color atlas. However, a Coloroid Colour Atlas is available that provides color exemplars at 16 levels of lightness out to as many as 13 increments in saturation for each of the 48 hue planes. Within the Coloroid system, color harmonies or "harmonics" can be defined through simple linear or geometrical combinations of colors.

References

External links

Coloroid color space
handprint.com. {{color space Color space