Yeah thats also what i thought. Anyhow, it may be as stated above that it could be the non dominate fish, or you could try to feed it krill to bring out the orange coloration around the finnage if its a gold saum anyway. Or you could just wait and see what happens, the fish might not be settled in, how recently did you get it? And maybe its female and not sexually mature,as when this occurs they are more colorfull. Well good luck.