The wings of blue morpho butterflies are iridescent blue — but contain absolutely no blue pigment! The color is achieved by tiny scales on the wings that have ridges, ribs and other structures that play with the physics of light at the nanoscale to reflect only bright blues. | Center for Biological Diversity

Despite its name, the blue morpho butterfly’s wings are not actually blue—their appearance is the result of the way light reflects off of microscopic scales on its wings. | National Geographic History