Entomologists disagree about the classification of Appias. Some consider that the South American species drusilla, and the African sylvia and lasti belong in this genus, while others prefer to place them in Glutophrissa. Disregarding those, there are about 23-28 Appias species, comprising 7-8 species from the Australian region, and 16-20 from the Oriental region.
Appias nero is instantly distinguished from other Appias species by the deep orange colour on the upperside of both sexes. In freshly emerged specimens this is very vivid, but the colour fades to pale orange-yellow after a few days. Males have dark veins on the upperside forewings but are otherwise unmarked. Females differ in having broad dark borders and a dark subapical streak on the upperside. This species is found from Sikkim to Singapore, and on the islands of Sumatra, Borneo, Sulawesi, Java and Palawan.