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

Purple isn’t on the spectrum, although violet is. Purple is a color your eyes see when both blue and red sensitive cones fire. The idea when mixing pigments is to have the unabsorbed wavelengths stimulate both the red and blue sensitive cones (and the best pigments for this are not necessarily red and blue).