The Three Color Cones in the Human Retina

ThreeCone2
The three color cones in the human retina resonate with specific frequency ranges of the light spectrum. These ranges follow a Gaussian normal distribution which center around Yellow or 520 THz, midway between the peaks of Red and Green. When the color wheel is then oriented around this point of symmetry, the complementary colors of Indigo and Yellow-Orange form an axis between primary and secondary colors. Tertiary colors then balance between these to create a 12-step color wheel.