I think most photos of caves I've seen have kind of lame colors. Probably because they use artificial lighting and the subject matter is basically just rock walls Usually limestone or something like that, since most caves are caused by the rock getting dissolved by water. Basically just bland off-white. And the conditions are usually cramped and otherwise terrible for photography. I quick search of Wikimedia Commons brought up a whole bunch of pics, but you said your internet was gimped, so I guess you can't look at them?
1 2 3 4 5 6 7 (There's plenty more there, which probably won't help you, due to aforementioned internet thing.)
Some of the rock formations are very pretty, but colors are basically dirty brown, dirty shadowy dark brown, dirty off-white, and black. In the ones taken against a cave entrance, you get a mix of searing white and almost black that might as well be monochrome. What's wrong with using black, by the way?
Anyway, what I'm going for is that flash photography of real caves doesn't really work for natural light in fantasy caves. I guess it'd mostly be blues and greens, with extremely heavy contrast between light and shadow. Maybe some sparkle here and there, with light reflecting from dwarven constructions, or exposed formations of ore or jewels. That tunnel's lit from the inside, right? There's something like a fire going on over there. Yeah, I'd suggest doing it the other way 'round. Use cold colors for surfaces lit by sunlight and warm for surfaces lit by people.