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

We can make cameras that see all kinds of “colors” we can’t – infrared, ultraviolet, microwaves, xrays etc.

We can also make filters in colors we can’t, like a filter that only lets infrared or UV light this.

So combine lots of filters at different wavelengths of light (“color”) with a camera that can see those wavelengths and we can find exactly what colors that objects reflect even all the colors our eyes don’t see.