Heritage
Blue is the rarest pigment in the natural world — and so, historically, the most expensive. Ultramarine, ground from lapis lazuli mined only in Afghanistan, was worth more than gold in Renaissance Europe; Vermeer's bills were enormous because of how much he used. Egyptian blue (the first synthetic pigment, ~3000 BCE) was lost for centuries and rediscovered in the 19th. Prussian blue (1704) democratized blue overnight; Yves Klein's IKB (1960) re-aristocratized it.
