I feed mine omega one cichlid pellets and shrimp pellets. he also eats HBH krill pellets and the flakes I feed the giant danios. Omega one or hikari is good and easy to find.
Crickets, Meal worms, Night crawlers, Hikari pellets, fish flakes, veggies. But his diet is defiantly one of the key things that will make him brighten up his color.
Some feeding suggestions try blackworms or brine shrimp Hikari makes some sinking carnivore pellets you might want to look into and frozrn feeders are alot healthier than live but still not as nutritional as a cichlid flake or pellet would be.