Are horses color blind?

Factual Questions
1

I’ve always assumed that horses were color blind. My daughter’s riding instructor thinks they’re not. She’s obviously been around horses more than I have, so I’d like to see a definitive cite, one way or the other.

2

Horses do have cones in their retina so, no, they are not colorblind.

3

Thanks for the clue. It helped me refine my search. I should have looked a little longer before posting. Dogs also have cones, but only 2 types, and not very many. Apparently they’re red-green color blind, and their blue-yellow vision is fuzzy. Cats have 3 types of cones, but not all that many, and their color vision is rather pastel. Horses seem to see about the same colors as people, though their accuity at shorter wavelengths seems to be in question.

http://www.animaleyecare.com/for.htm#Vision In Dogs, Horses, and Cats
http://www.animaleyecare.com/learn.htm#VISION IN ANIMALS