"Structural color" in butterfly wings

YouTube link.

Scientists study the process in vitro in order to document the development of nanostructures that give the appearance of color without having pigment themselves.  Interesting.

Addendum:  A tip of the butterfly-chasing hat to reader Drabkikker, who offered a link to an article at Atmospheric Optics in his comment.  Everyone who enjoys the video should also read that link.

Reposted from a couple months ago because the information in the link mentioned above has now been incorporated into a video:

YouTube link.