Ok let me tell you what I think so far, correct me if I'm wrong. You get corals that are very colorfull. You put them in your tank. As they acclimate some become browner (less colorfull) right. You put those browner corals closer to the light and they evict some of the zooxanthellae as they don't need as many to produce the amount of food they need. Right? I've read in many places that zooxanthellae are mostly brown in color... This is what I think so far so heres two questions. Q1. Why is it that when coral bleach they turn white? If they evict the zooxanthellae shouldn't they show as much true color as they can at this point? Q2. My tank crashed a couple months back. The corals didn't have light for a couple months. Most bleached white but are alive. Everything is set back up now better than ever and all my corals are on the road to recovery. The colors they are taking up aren't like the original reds, orange, purples, etc. They are mostly taking up green and brown. Will the original color come back with time?