not the lighting at all. I do agree, it is definetly the same species, but some are mostly blue, mostly green, or mostly red. The one the admiral's got is a red one (seen it myself). I can see why each color is sold for different price, probably some are more rare than others. But it is the same species. Maybe their from different regions?
Either way, his is awesome, and it eats pellets and just about anythin u put in the tank thats small enough for him to eat... so much for being a picky eater ^__^