The Danaid Eggfly butterfly is one of the most common on the African continent.
The males have iridescent colours (physical colours). They have large white spots which, when observed from the front, appear surrounded by a bright blue ring.
The blue cannot be seen from behind. This blue colouring makes males attractive to females. The fact that the colour is only visible from a certain angle probably allows them to be less noticeable to predators.

origin: Tropical Africa