So far there is no color lost of my fish. The color intensify when he is excited. My Bluethroat is much more colorful now than when I first got him. Certainly most colorful when he flash. This is a rare treat for me. Since he is the only fairy wrasse in my tank, he only flash when I put a mirror on the tank. I cannot take picture easy when he is flashing since he is right up against the mirror and he is soooo fast.
I think in a larger tank, with other Fairy Wrasse, he will be a stunner. Below are two picture from yesterday when he was not excited and one when he is excited. Sorry for the poor picture but I use this to show the color, not how beautiful my wrasse is. It is hard to take picture of this fish, with a cell phone since I don't have my camera at work. The tank is my office tank.
IMO, the throat color is more of a state of mind of the fish rather than permanent colors that may loose due to inadequate nutrition in captivity.
Normal State
More Excited state
