Since yellow is the spectral color between red and blue, why do we get purple when mixing red and blue pigments together and not yellow (the average wavelength)?

looney_tunes

Light doesn't 'average'. The color of pigments depends on the wavelength of the light that is not absorbed by the pigment. This is rarely a single wavelength, but is a mixture whose dominant wavelengths determine the color we perceive. Red objects reflect mostly red light; blue objects reflect mostly blue light. When you mix them, if they were perfect spectral colors you would get black, because the red bit of the pgiment would absorb everything except red, and the blue bit would absorb that. But since they each actually reflect a range of frequencies, things get more complicated, and the color depends on exactly what wavelengths were reflected by each of the original pigments. Subtractive color mixing is usually shown on a color wheel. You will note that yellow is directly opposite purple - they are complementary colors; in the red,blue,yellow system of primary colours, purple (or violet, more precisely) is a secondary color, along with green and orange. In modern color printing the three primary colors are usually cyan, magenta and yellow. http://en.wikipedia.org/wiki/RYB_color_model http://en.wikipedia.org/wiki/CMYK_color_model Feb 28 12, 5:19 PM