It's however your brain interprets it. Like things in general are only certain colors because that's how your brain sees it. So in perspective everyone could see every color differently and not know it, because what we all call one thing could look completely different to everyone else. For example, my text is pink, we all agree that is it pink or some form of pink, but for all we know I or anyone else could be seeing a different color. It's just that we have all come to learn, know, and accept that what we see here is 'pink.' herpderpdone
things are certain colors because they absorb all colors besides one that they do not absorb and bounce off into our vision Example: plants bounce off green but mirrors are all colors