Comment by layer8

That’s assuming that there is something like a “true” internal color that external colors are mapped onto. I think it’s more likely that for the brain, “red” is just “that hue signal range that red things have”. Which is roughly the same for everyone (modulo color blindness), in the sense that if one person sees two objects as red, another person will also see them as the same color, and will perceive the same brightness and hue relation relative to other objects with adjacent brightness and/or hue.

Meaning, there is no absolute color, the brain just learns what things have the same color, and how similar or dissimilar they are in hue to other objects. And for example “cold” colors are cold because we associate them with cold things, not because of some independent “qualia”.