Both species are considered to be relatively common in both locations.
Pomacentrus maafu is primarily brown to dark brown on the body with variable amounts of yellow on the head and adjacent anterior body, the perch also has a yellow caudal fin.
Most scales on the posterior half of the body have a narrow blue posterior margin.
Three rows of blue spots can be seen on the cheek, corresponding to the rows of scales.
A short blue stripe runs from the center of the upper lip to the anterior margin of the eye, and a blue stripe runs along the upper and lower portions of the iris.
On the upper base of the pectoral fin and on the upper edge of the gill opening runs a similar large grayish spot.
There is also a small blue spot on the dorsal surface of the caudal peduncle.
The dorsal and anal fins show a light blue margin.
The pelvic fins are brownish yellow with a blue anterior margin, and the pectoral fins are translucent yellowish.
Some individuals have a greater amount of yellow coloration, especially on the anterior half of the body and the posterior portion of the dorsal fin, so fish individuals from Tonga are generally darker brown in coloration than fish from Fiji.
The species name is called "maafu" in reference to Enele Ma'afu'out'itonga, commonly known as Ma'afu (1826-1881), a Tongan prince and warrior who emigrated to the Lau group in Fiji at the age of 22, and eventually became the leader of the Tongan community there as well as a Fijian chief.
He was a man of two kingdoms and as such his influence reflects the geographic distribution of Pomacentrus maafu.