Depending on the light they may look black or dark blue they’re entirely dark blue in colour. Despite it’s dark colour it’s a stunning fish that only shows it’s true beauty once settled, so if you’re looking for an uncommon but affordable dwarf angelfish, this would make an excellent choice.
Like all other angelfish it's hermphroditic and the most dominant fish will turn into a male when there is no other male around.
These fish are quite peaceful. Although dwarf angels are certainly more likely to be reef safe compared to their larger relatives and thus seen more often in reef tank, they're always a risk. Fiji Blue Dwarf Angel is considered relatively reef safe, feeding mostly on algae, but some individuals might harass certain LPS corals.
Keeping them well fed seems to reduce the risk, so make sure to feed them a proper varied diet of algae and chopped meaty foods to make them really happy!