From the Dwarf Angelfish family, this is a Coral Beauty - Centropyge bispinosus. This fish came with the 55g setup I bought, and recovered its original colors in a year's time. These fish are quite shy and love to retreat into safe hiding places. So elusive, that I couldn't get a good shot, but Travis did. It will not get along with other dwarf angels in smaller tanks, but in a larger system it should be okay. Reef-safe.
Photo by Travis Staut