This afternoon I went to a talk about structural colour in Hibiscus, during which I remembered about these Lamproderma slime moulds that also display this phenomenon (although with a different physical basis). Many species are restricted to the snow-line in montane Europe. Beautiful things.
I’m going to read this review article to learn something about structural color. I remember learning that bluejays use structural color to make their feathers appear blue, by reflecting light in the blue range. If you hold one up to the light, you’ll only see gray.
I’ve never seen slime mold like that though. This must be thin film interference? And the hibiscus is a diffraction grating.
Haven’t done much science reading in the past few years so this will be fun.