A copy of this page should be in every future Physics textbook...

It shows to us just how skewed our (human) perception of light really is.

It also shows to us just how much is going on, in terms of combinations of wavelengths present, with various light sources, and just how different, again, in terms of permutations of constituent waves, any two of them are...

Anyway, a great page that should be included in any future Physics textbook!