Have you tried some Hikari cichlid gold pellets? They have made the color on my oscar brighten a lot.
Omega one makes a color enhancing pellet. It has stuff in it that helps bring out red pigments.
How is the water chemistry. Like nitrates, nitrites, ammonia, and Ph. What is the temp. How big is the tank.
You really need a test kit.
Do you know one that I can get thats accurate