I don't think the OPs question deserves the approbation levelled out by OCUK. It's a question that a lot of greater thinkers have asked and struggled with.
In actuality we know that people have slightly different colour perception. Colour blindness, aside, there are multiple alleles for each of the three pigments used in colour perception, some of these respond to slightly different wavelengths of light. It is implausible that people with different pigments will have identical perceptions, I believe this has been experimentally tested but I don't have a reference handy.
Additionally, there is a yellowing of the lens as you age, so your perception of colour shifts as you grow older.
So there is
some variation in how people perceive the same colour, the question is whether these can be big ol' red for green substitutions. I think the answer to this is 'no'. The efficacy of colour blindness tests
requires that we perceive colours in a manner that preserves contrast; this means that most substitutional arrangements you can image would simply not work. Combine this with the fact that colour gradients are universally perceived as smooth and I think you can entirely rule out other colour schemes. I don't believe there have been any definitive studies carried out based on this idea though.
There was a whole horizon episode about this... the most interesting bit is the himba part, I can't remember the exact details but it seemed to suggest that they actually do see colours differently because of the colours that they see, use & name in their daily life - they had more difficulty distinguishing between certain colours that we can easily tell the difference between & vice versa for us.
Yeah, this is basically tosh.
If you have a name for a colour, you're better at remembering it. Makes sense, really, doesn't it? Instead of trying to remember a colour in abstract, you're now trying to remember a colour
or a word - that's easier, so you're going to be better at remembering it.
Similarly the "differentiating" test is widely misinterpreted. What basically happens is you put up a bunch of coloured squares and ask "which one is different?" Then person A looks at the squares and goes "blue, blue, aquamarine - ah! The aquamarine is different" quick, there's the answer; person B goes "blue, blue, blue, huh? They're all blue, well, I guess that blue is more greeny, isn't it? They probably mean that blue, don't they?" a little slower.
Neither experiment provides compelling evidence of differences in colour perception. Were colour perception actually altered by the words used then you'd expect people to be
unable to distinguish the colours - that isn't the case. What's more, if you give them tasks that rely on differences in colour but aren't asking them to look for differences, there is no difference in reaction time (for example if you showed them an aquamarine horse on a blue background and asked them what the picture showed, A & B would react in equal time).
