How come red & purple are on opposite, far ends of the electromagnetic spectrum, but when mixing colors together in kindergarten, purple is halfway between red & blue?

Question

Shouldn’t common sense dictate that either both be one, or both be the other?

In: 1934

Answer 1

When we stick purple (or violet) at the end of the rainbow, that’s not actually a good representation of wavelengths of light.

Purple does not fit in with the other colors, because there is not a purple wavelength of light. We only perceive purple when there is both red and blue light present. Pure frequencies can make red, green, yellow, blue, etc. But purple is a consequence of our brains interpreting the world around us.

This is why we represent colors with a color wheel, and frequencies with a straight continuum. The rainbow goes from red to blue, but our brains can blend red and blue together with a unique visual color.