Which color model is based on cyan, magenta, yellow, and black?

The color model that is based on cyan, magenta, yellow, and black is CMYK. This model is widely used in color printing and works by combining these four colors to produce a broad spectrum of other colors. The "K" stands for black, which is added to enhance depth and detail, as the combination of cyan, magenta, and yellow alone does not produce a true black.

CMYK operates on a subtractive color mixing principle; this means that as colors are added, the light that is reflected becomes darker. In contrast, the RGB model, based on red, green, and blue, is additive and used primarily for digital displays where colors are created by adding light. RYB and HSB are less common and used in different contexts, which do not pertain directly to traditional color printing methods.