It is so fun growing them out. Keep up with weekly water changes and feed a good pellet and some occasional baby mysis shrimp and they will get big in no time.
I feed mine 4 times a week right now. They get a combination of biggie Xtreme pellets, Hikari frozen krill, and Hikari frozen jumbo mysis throughout the week. Once I started adding more frozen food into the mix their color got much better.
I have them in a 125 gallon with 6 petricola cats and a WC Altolamprologus compressiceps crocodile island trio.