Lessons of iridescence: what experientialist art can teach us about color perception

Peacock feathers, opal gemstones, and soap bubbles gleaming in the sun tend to leave us spellbound, not only because they are strikingly luminous but also because they change in color as their viewing or lighting angle changes. This optical phenomenon is known as iridescence (from the Latin iris / irid -, meaning ‘rainbow’), and it can be subtle or pronounced. The crown of an Anna’s hummingbird, for example, can go from dark brown to a saturated hot pink in the blink of an eye, depending entirely on one’s perspective and the movements of the creature itself. Given the natural allure of iridescence, it is unsurprising that a wide variety of human-made materials have also been developed to mimic it, ranging from car paints and nail polishes to window films and textile fabrics. Artists, too, have long experimented with iridescent materials in order to dazzle their viewers. In the seventeenth century, court painters in the Hindu kingdom of Basohli pasted iridescent beetle wings onto their paintings to give them an emerald-green shimmer. And much earlier, in ninth-century Mesopotamia, potters applied lusterware techniques where thin coatings containing unoxidized metals imparted iridescent glazes to their ceramics. As these artisanal traditions indicate, the artistic use of iridescence has been a rather niche practice historically (see Finet, 2023 ). Indeed, it was not until the emergence of novel synthetic technologies and manufacturing processes in the 1970’s that mass-produced iridescent materials became more widely available to the artmaking public.