he seems big to be fading. are those spots raised at all? could he be scratching himself on something? is there a female that he can see? i have one fish that whips himself against the gravel when there is a female in the tank. he scratches the crap out of himself and looks really bad when this happens. he is not a fh though.
my FH lost its red and turned dark in my black back tank. I added white gravel; the black went away and it got brighter/whiter. i've recently added red pebbles; and guess what, it's starting to show more red.