Structural color -- that's engineer speak for a reflective display that mimics iridescence.

ENGADGET: Peacock feathers form basis for reflective displays, could bring color to e-readers soon

They are flashes of iridescence, their wings beating so fast they are virtually invisible, their beaks as thin as needles.

BBC: Hot springs and hummingbirds in Ecuador

Intriguingly, that did not apply to birds that used melanin, another pigment, in their plumage, nor to those that employed iridescence which is a result of the structure of feathers, rather than their chemistry.

ECONOMIST: How an industrial accident has helped evolutionary theory

Columnar in shape, falling from the shoulders to the ground, with sometimes a silk cord at the waist or under the bust, it is made from China silk that has been hand-worked into thousands of vertical pleats a process invented by Fortuny, and one that invests the silk with both iridescence and a springy eternal life.

WSJ: The Rich Pleasures of Pleats | Fortuny | Spanish Institute | By Laura Jacobs