The Bicolour (also Bicolor) Chromis is native to tropical reefs of the Indian and western Pacific Oceans. The adult has a black body and a white tail that may include the back of the body and dorsal fins. The fish grows to 9cm long and is sociable. Diet is zooplankton.

There are several small chromis that are black or dark brown at the front and white at the rear. The Bicolour has only a small area of white; the Half and Half Chromis, Chromis/Pycnochromis iomelas, of Indo-West Pacific has a ratio of half dark and half white, as named. Only in 2013, the Chocolatedip Chromis, C./P. dimidiata, with about twothirds dark and one third white, was split into two species: the Two-tone Chromis, C./P. fieldi, was created for the Indian Ocean chromis and the Chocolatedip name remained for the Red Sea species. Above is thought to be the latter.