How can we observe if an object is a color we can’t see?

Question

From what I understand, humans can see red green and blue and everything in the middle. Some animals I’ve heard see more colors than us, so what’s to say that some things in nature are colors that we don’t see? Who’s to say that some apples are red? And instead a different color that we don’t have a name for because we can’t process it?

How can we tell if this “apple” is as a matter of fact “red”.

In: 75

Answer 1

Stephen King (I think) wrote a short story about some kind of predator (bear, maybe) that was born with a mutation that gave it a color that humans can’t see.