primary colors, a small number of fundamental colors. In visual science these are red, green, and blue, the colors specifically picked up by the retinal cones. Mixtures of varying proportions of the primary colors will yield white light in addition to the 150 discriminable hues of normal human vision. In painting and printing, the primary colors are red, blue, and yellow. When combined properly, these colors yield black and all other visible hues. See also prismatic colors.
