I have a 48 gal cichlid tank with two Acei, three yellow labs and two hongis. The hongi almost always remain a dull blue color even though they are over 6 months old. Occasionally one will brighten up and look beautiful, but not nearly as much as I would think they should. Is this unusual? I've read somewhere not to keep two labs in a tank together but they seem so different in color I wouldn't expect it to be a problem. Any ideas?