The sunset moth was described in 1773 and initially classified with butterflies, later with the swallowtail genus Papilio, before being recognised as a uraniid moth. The confusion is understandable: it flies in daylight, holds its wings in a butterfly-like fashion at rest and is one of the most vividly coloured Lepidoptera anywhere.
The colour is not pigment. The iridescent bands come from ribbon-like scales containing stacks of chitin layers separated by air; interference in these stacks produces the shifting greens, oranges and blues, and the effect changes with viewing angle. The curvature of the scales spreads the reflected colour over a wide range of directions, which is part of why the moth appears saturated from almost any position.
Larvae feed exclusively on Omphalea, a genus of euphorbs containing toxic alkaloids, and sequester those compounds into the adult. The bright coloration is generally read as aposematic. Adults move seasonally between populations on the eastern and western sides of Madagascar as their host plants defoliate, but the details of these movements are only partly documented.