CMYK Systems

Color vision is based upon the responses of three classes of cones in the retina, each of which has broadband sensitivity but maximum sensitivity at different wavelengths. A consequence of this is that color reproduction is trichromatic – the use of three primaries allows a wide range of colors to be reproduced. Color-mixing behavior can be broadly classified as either additive or subtractive. The optimum primaries of the subtractive color system are cyan, magenta, and yellow. The use of cyan, magenta, and yellow subtractive primaries allows a surprisingly large – albeit limited – gamut of colors to be reproduced. In practical printing systems, black is also used so that CMYK is ubiquitous in printing. Extended gamuts can be achieved using more than three or four primaries and systems based on six or more primaries are becoming quite common.