Female convict cichlids display a yellow-orange color on the belly and dorsal fin, according to About.com. The color patches are more pronounced just before laying eggs. Females are also smaller and rounder than males, which eventually grow a nuchal hump, a fatty deposit on the forehead, as they mature. The male's foreheads are steeper than the female, and their fins are longer and more pointed.
Both genders of convict cichlid are primarily blue-gray in color and display the dark vertical bands that give the species its name. These bands are known to change color in response to the mood of the fish, getting darker or lighter. Both genders also display more intense coloring when ready to spawn.
A study published by the National Center for Biotechnology Information notes that the orange coloring found on females elicits aggressive behavior from other females, though not from males. Convict cichlids are known to be aggressive and territorial in general, especially while breeding. About.com reports that they are even known to kill larger fish and recommends that a breeding pair be kept in its own tank. Non-breeding convict cichlids may do well paired with other South American cichlids, although the other species should be larger to reduce the chance of aggression or at least even the odds should aggression occur.