I don’t know about horses, but, as ol’ Ben Franklin said after a life of laborious research, all cats are gray in the dark, so the same probably applies to other mammals.

Everyone, for centuries: There are no black swans.

The Dutch, 1697: Y’all will not believe what we found in Australia.

Multiple horse theory confirmed?

Thise are literally the same color.

That only disproves it for some definitions of color. If we define color as “not colorless” or even as “visible”, then they are still all the same color (all one of it).

For the less educated, like myself: https://en.wikipedia.org/wiki/All_horses_are_the_same_color

Horses are a lie

All horses are the same color… spectrum. 😌

Sewer hose