I just purchased my yellow tang today, he was fine in my 40g tank. He had been in there for 5 hours. When I turned off the florescent lights he went pale and hasn't regained his color for 40+ minutes! HELP!
How did you acclimate the fish? It may be stress? was she in the bag long? I would give her about 3-5 days might start looking normal after she gets used to her new home.