make sure your water is in great condition. And leave the lights on. They will be somewhat dull after the light has been off for a while. And what size are they? mine didnt start to get their nie colors until around 10 inches
water is perfect i have a wet dry 150 and a fluval 405 on the tank its crystal clear and has NO odor, i leave lights on about 10 hrs a day. off at night, his main diet is feeders,trying to break him of that. hes about 6-7 inches