I have heard from many people that the color of an animal's environment sometimes helps the animal release colors.
Many animals try to reflect the colors of their surroundings to blend in more due to safety reasons or so.
I have noticed many many times, a lot of FH breeders... keep PINK gravel with pink FH, green and blue gravel with similar color FH.
If the color of the FH is so bright already, won't they have put it in a darker backround to make the FH color stick out more?
Im not sure still, but Im going to try to lighten my tank up, with white sand, blue backround, real AND artificial plants to see if it makes any changes.