On Vision and Colors from a prism, however, the production of white can be demonstrated by using a mixture of colored light from each of the three main pairs of complementary colors: red – green, orange – blue, or yellow – violet. White can be produced from two complementary opposite colors when both of the external causes of the colors excite the same retinal place at the same time. Newton claimed that white could be produced by the aggregation of his seven prismatic colors. He erroneously considered color to be in light instead of in the eye. White is the result of the combination
Color source. Dominant wavelength is roughly akin to hue. There are many color perceptions that by definition cannot be pure spectral colors due to desaturation or because they are purples (mixtures of red and violet light, from opposite ends of the spectrum). Some examples of necessarily non-spectral colors are the achromatic colors (black, gray, and white) and colors such as pink, tan, and magenta. Two different light spectra that have the same effect on the three color receptors in the human eye will be perceived as the same color. They are metamers of that color. This is exemplified by the white