A color belonging to any of three groups each of which is regarded as generating all colors, with the groups being:
a. Additive, physiological, or light primaries red, green, and blue. Lights of red, green, and blue wavelengths may be mixed to produce all hues.
b. Subtractive or colorant primaries, such as magenta, yellow, and cyan (used by printers) or red, yellow, and blue (used by painters). Substances that reflect light of one of these wavelengths and absorb other wavelengths may be mixed to produce all hues.
c. Psychological primaries red, yellow, green, and blue, plus the achromatic pair black and white. All colors may be subjectively conceived as mixtures of these. color