Most BPs refuse food when they're stressed (poor husbandry) or seasonal changes. They're really creatures of habit and routine, so I'd say switching up food "breeds" regularly is more likely to cause problems than sticking to the same prey type every meal. As for "colors" - I've heard that depends on the snake! Some will only eat white rodents, while other don't seem to care about color at all. I don't think it would hurt to feed a mix of colored and white rats, but wouldn't go out of my way to select food based on color (unless your snake shows a preference). Anyways, just my $0.02!
Neat! Bioactive enclosures aren't common around here, so it will be interesting to see what yours looks like and how it works when it's finished!Was planning to go with a bioactive setup as the adult build