As is they mature, the blue changes to olive green, with the white vertical bar on the flanks widening and becoming more yellowish.

They may retain yellow areas along the margins of the dorsal and anal fins, and there is a dark ocellus visible behind the operculum.

[2] Holacanthus africanus is found from Senegal to the Congo River estuary, including the Cape Verde and São Tomé islands.

[4] Holacanthus africanus is found in clear water over rocky reefs at depths between 1 and 40 metres (3 and 131 ft).

[5] Holacanthus africanus was first formally described in 1951 by the French ichthyologist Jean Cadenat (1908–1992) with the type locality given as Gorée in Senegal.