Why Do These Plants Have Metallic Blue Leaves?

Ooh, shiny

ED YONG

Roses are red but violets aren’t blue. They’re mostly violet. The peacock begonia, however, is blue—and not just a boring matte shade, but a shiny metallic one. Its leaves are typically dark green in color, but if you look at them from the right angle, they take on a metallic blue sheen. “It’s like green silk, shot through with a deep royal blue,” says Heather Whitney from the University of Bristol.

And she thinks she knows why.