“Inverted Spectrum” is a philosophy that states the possibility of people agreeing on the names and characteristics of certain colors, though one person is essentially seeing a totally different color. If I have an inverted spectrum, we both say we see a bright blue sky, but if you saw it through my eyes, you could be looking at a bright red or purple or green sky. Compare to the fact that dogs are proven to have a very limited spectrum of color, humans may also be born with access to a limited or inverted spectrum, and never be aware of it.