Cie Color Model - Xerox Fiery color server User Manual

A
A-3 Desktop Color Primer

CIE color model

In the 1930s, the Commission Internationale de l'Eclairage (CIE) defined a
standard color space, a way of defining colors in mathematical terms, to help in
the communication of color information. This color space is based on research on
the nature of color perception. The following CIE chromaticity diagram is a
two-dimensional model of color vision. The arc around the top of the horseshoe
encompasses the pure, or spectral, colors from blue-violet to red. Although the CIE
chromaticity diagram is not perceptually uniform—some areas of the diagram seem
to compress color differences relative to others—it is a good tool for illustrating some
interesting aspects of color vision.
By mixing any two spectral colors in different proportions, we can create all the colors
found on the straight line drawn between them in the diagram. It is possible to create
the same gray by mixing blue-green and red light or by mixing yellow-green and blue-
violet light. This is possible because of a phenomenon peculiar to color vision called
metamerism. The eye does not distinguish individual wavelengths of light. Therefore,
different combinations of spectral light can produce the same perceived color.