Color Vision - WIP

The Three Cones

There are two main types of cells in the human eye that respond to light: rods and cones. Rods are primarily used in night vision and have little sensitivity to color. Cones on the other hand are very sensitive to color and function best in daylight.

There are three kinds of cones: Short, Medium, and Long, not named for their size, but the length of the light wavelengths each is most sensitive to. Contrary to popular belief these are not Red, Green, and Blue cones, nor are those three colors the only colors the human eye can see. We can see the other wavelengths too, they are not just mixtures. While these cones do peak at three different wavelengths, their ranges are wide and overlap each other.

diagram showing the range of each cone cell along the visible colors of light. S-cones range from 400nm to 525nm, peaking at 450nm blue, covering violet to teal. M-cones range from 410nm to 650nm, peaking at 550nm green, covering violet to red. L-cones range from 410nm to 700nm, peaking at 575nm yellow, covering voilet to red. — cone wavelength range diagram from the wikipedia page on cone cells

While Small cone cells peak at blue and Medium cone cells peak at green, Long cone cells do not peak at red, but instead yellow

Trichromacy and Opponent Process Color Theory

Normal human color vision is called trichromacy because of the three different color sensitive cones, although our eyes do not necessarily read individual colors like how RGB displays mix colors.