I just started keeping cichlids. Within the first week I noticed my EBJD and Gold Severum were looking pale, I know fish don't get pale, but that's the best description. The colors were fading and looking dull. It only took my firemouth 2 days to bleach out. I heard different opinions but had a general consensus that white substrate will bleach out otherwise bright fish. Black is good, but honestly I have gone through black and now natural river gravel, they look best on the darker natural gravel. On white gravel all of my fish other than the green terror and Senegal bichir washed out. Color came right back when on a darker substrate. I know your problem was solved IE babies, but you might get better colors out of them on a darker substrate