The male upperside is black dusted with blue. On the underside, the hindwing has a red tornal patch and both wing bases are red.

The female forms esperi, butlerianus, agenor and very rarely, ityla are found in Singapore. The form butlerianus was recently spotted on the island of Pulau Ubin, one of Singapore's offshore islands. This form has not be seen on the main island in recent years. The caterpillar resembles that of the Lime Butterfly, but grows to a much larger size. The pupa is suspended with a girdle as in most Papilionidae pupae.