>>10650646>Why are black, brown, red(orange/ auburn type), and blond the only naturally occurring hair colors in humans.Those are all shades of brown.
Basically it comes down to the fact that the common ancestor of mammals was noctournal and it didn't need all those additional cones in their eyes to see a wide range of color since it was hard enough just to see anything. This is why mammals have much better noses and ears than other animals.
If you can't see in color then having pigments on your body you can't percieve isn't going to be useful and so its not going to be selected for.
A lot of those colors you see in other animals arent pigments, but microstructures that cause light to bounce and refract.
The yellow of bumblebees or wasps for example is being studied to create more efficient solar cells because of the quantum effect photons have when being absorbed.
There was a PBS Eons episode about this I cant find right now, but eons is pretty great so its worthwhile to watch some videos if you have a passing interest in natural history.
