Oh, is this your "baby" girl? Your "other" bigger female looked very blue in your other thread pic. I "think" electric blue coloring is more genetic than some colors that may need dietary inhancements to look their best. If that's right, she just needs to grow to look her best. A nice variety of foods may help her grow into her full potential. Look for foods that the first 3 ingredients are fish, seafood, & algae or veg. Fish meal is ok too; but not wheat, corn, rice or soy type foods. Those last 1s are fillers, not anything they'd see in the wild. Blood worms & shrimp of appropiate size, etc. are treats for a couple times a week, not a sole diet.
Keep a variety of food & offer them on a rotating basis. You don't want to encourage fussy feeding. That can cause problems if suddenly you run out of a "favorite" & can't replace it soon. Fish should always be a little hungry & eat what is available. Young fish might get fed twice/day; adults should be good with 1 feeding. Adjust amounts as needed; more food = more poo = more water changes. To grow young fish faster you need to up your game on those & stick to it.