In the continuum of visible-light colors that makes a rainbow, we have red, orange, ... blue, indigo, and violet. But aestheticists tend to join the two ends together to make a "color wheel". They use this to predict pairs, trios, or quads of colors that are symmetrically placed in the wheel and therefore look nice or bad together. But, why does the continuum map to a circle at all? [more inside]
posted on Nov 30, 2006 - 21 answers