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

I wanna give it a shot too:

Yes, magenta light doesn’t exist.
But! The way we see color is by using bits in our eyes that tell us how red, green, or blue something is, which the brain then mixes to get the other colors, for example, yellow is a bit green and a bit red, so if the green and red bits light up, the brain knows to mix those into yellow.
If something is throwing both red and blue at us, the red and blue parts will tell the brain so, and the brain doesn’t know that light that is “a bit blue and a bit red” cannot exist, so it mixes it into making magenta.