3 month old fry no color?

[Marleah]

Hi there, I have approximately 6 fish fry that I randomly found in my large tank. One is platy fry that's about 3-4 months old and the others are black Molly/guppy hybrids which are just over a month old. None if my fry have any color what so ever. The 2 largest ones have some black speckling on their fins and tails but that's about it. I fed them first bites and blood worms for the first month and now have them on fine powder color enhancing food with blood worms. Is it possible they just won't develop color? This is my first time raising fry so any help would be appreciated!