I noticed that when the babies were in a tank with black substrate and not very much sunlight at all, they seemed to be black on black as far as coloring goes...
about a month of having them in a different tank and they really lightened up and greened up...substrate is green with black specks...so i credit mr. golden sun for their coloring
btw tank on the right is a 50 acrylic with a thai silk flowerhorn.