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

I’m color blind in a certain range.

One of the dashboards at work has a red/green/yellow stoplight for each process. The app developer chose a green and a yellow that I can’t discriminate. And there’s no other indication other than color.

The summary at the bottom says 3 red 4 yellow 12 green. All I can see is 16 yellow/green circles. Someone else can walk up and point to the four yellows quickly.