On the upperside, the Common Palmfly (Elymnias hypermnestra) is bluish-black with a series of blue submarginal spots on the forewing. 
The underside is a speckled brown with a lighter shade "thumb-print" at the apex of the forewing. 
A white spot can be found in the centre of the costa on the hindwing, but this can be absent or inconspicuous in certain specimens.

Ben Tre area, Mekong Delta, Vietnam, 23 December 2023