I love iridescence in nature. Think of the shimmering colours on peacocks’ tails, on butterfly wings, on the bodies of dragonflies. It turns out that this type of colour in nature is called “structural color”. It is produced by light reflecting nanostructures rather than pigment. And apparently it is jolly hard to replicate outside of lab conditions. Apparently, MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) researchers have replicated nature’s brilliance with a new optical system called MorphoChrome, a handheld device that can be used to “paint” with multi-colour light onto holographic film. This painted sheet is then applied to 3D-printed objects or flexible materials used in, for example, fashion items. Fascinating!