It depends on the fish's genetics, it may or may not develop more color, however if it doesn't have fader genes there is a good chance that it's color won't change.
Fish needs to have red pigment cells to get red color, just food won't do.
Agreed, can't enhance what not there to begin with. It would basically be the same as feeding a blood parrot foods that boost blue color, if it ain't got it to begin with it won't suddenly develop it. Honestly if I was the OP I would be happy with how he looks already, I like the nice steel blue all over him with the well defined flowerspots. Hard to find em with such a clear, cut and dry definition between colors.
Nice looking fish. I like the white eyes and patterning. With proper care I think his fins and face will darken up which will contrast well with the solid colored body. Dont give up on this one!
