But does the Foveon sensor use RGB filters or does it work with different frequency bands? That's a major issue with science data - it doesn't contain RGB data for the most part, because that's not what scientists are interested in.

What's the correct colour channel to use for for near UV (yes, I know that some people - mainly women - can perceive that, but the vast majority of people can't)? What matches near IR or even X-rays? How would you colourise the frequency bands that match different elements (those include very narrow bandpass filters) but don't really make sense in terms of RGB?

That's the difference right there. If you have a picture that uses channels of different filter bands that correspond to hydrogen bands, organic molecules or UV radiation, none of that data correlates to human colour perception. So someone just chose shades of green for hydrogen or shades of blue for organics.

So what I'm trying to say is that the underlying mechanism is irrelevant - the data simply isn't colour data as seen by humans.