Young-Helmholtz theory of color vision [Thomas Young, English physician, 1773–1829; Hermann L.F. von Helmholtz, German physician, physicist, and physiologist, 1821–1894] , the concept that all color sensations are mediated by three types of retinal receptors, which correspond to three primary colors: red, green, and blue-violet. By their individual and combined activities, the receptors produce the perception of all visible hues.
