The Materialist's Theory of Colour Experiences

I think it's obviously true that people might have three different colour experiences. Does that mean I could be having an experience which I call red, but you would call green if you were having it? And vice versa. So I think we should acknowledge that as a possibility. What the materialist has to say of course is that at some level, functional or behaviour or neuroscientific, you can detect this difference. But I do think if you pound two groups of people who are behaviourally and neurophysiologically and information processing identical then you'd have to say they have the same experiences. You've described how you've changed your opinion about the right conclusion to draw from your thought experiment.