[kazinator]

> To get something purple, you’d need to find a material whose electrons were excited by low-energy red photons, but had no use for higher-energy violet photons.

Nope! Purple is not violet! It a color that the eye perceives when stimulated by both blue and red wavelengths at the same time; there is no wavelength that produces purple by itself.

[goatlover]

I think this and other facts about how we see color demonstrates that colors are not out there in the world, but rather a conscious perception of how we see the world, with animals having varying color schemes, some colors which we don't see, depending on their eyes and brains.

Why should only visible EM radiation have colors, but not radio, X-rays, etc?