CMY color model in the context of "Color printing"

The CMYK color model (also known as process color, or four color) is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. The abbreviation CMYK refers to the four ink plates used: cyan, magenta, yellow, and key (most often black).

The CMYK model works by partially or entirely masking colors on a lighter, usually white, background. The ink reduces the light that would otherwise be reflected. Such a model is called subtractive, as inks subtract some colors from white light; in the CMY model, white light minus red leaves cyan, white light minus green leaves magenta, and white light minus blue leaves yellow.

Color science is the scientific study of color including lighting and optics; measurement of light and color; the physiology, psychophysics, and modeling of color vision; and color reproduction. It is the modern extension of traditional color theory.

A color wheel or color circle is an abstract illustrative organization of color hues around a circle, which shows the relationships between primary colors, secondary colors, tertiary colors etc.

Some sources use the terms color wheel and color circle interchangeably; however, one term or the other may be more prevalent in certain fields or certain versions as mentioned above. For instance, some reserve the term color wheel for mechanical rotating devices, such as color tops, filter wheels or the Newton disc. Others classify various color wheels as color disc, color chart, and color scale varieties.