Eli5 How is frequency related to perceived color?

Question

What’s the mechanism behind translating a wave frequency to a color for a human?

In: 8

Answer 1

Hi. Doctor here.

Frequency and wavelength of light are a measure of the energy of that light. Since color does not exist in reality, and is an invention of the brain to make sense of the different wavelengths of light the retina detects, the color receptors in the retina fire at different rates under different wavelengths. Those combinations of firing rates of all 3 receptor types is processed in the brain to produce what we perceive as color.

For example, let’s say a light with wavelength of 650nm makes the color receptors fire like this:
Red: 98-100%
Blue:0-1%
Green: 0-1%

This 100-0-0 combination in brain means Red. So we perceive the color red.

Hope this helps. 🙂