Carmine

Spain took control of the trade after the conquest of Mexico and kept its source secret for over two hundred years. Europe knew cochineal was worth an enormous amount and did not know what it was, theories included a seed, a berry and a worm. It was the second most valuable American export after silver, and the Spanish crown's monopoly held until the eighteenth century, when specimens were smuggled out and cultivation started elsewhere.

It made red available to anybody who could pay, and 'anybody who could pay' meant institutions. Cardinal's robes, the red of British army coats in some periods, Venetian scarlet, and the crimson of countless portraits are cochineal. The Zapotec weavers of Oaxaca who invented the technique saw very little of the money.

Then aniline dyes arrived and destroyed the market, and then, in the twentieth century, the market came back, because cochineal is a natural food colourant and the synthetic red alternatives had regulatory problems. It is E120 on an ingredients list, and it is in yoghurt, sweets, sausage, lipstick and certain famous red drinks. Every few years a brand discovers that some of its customers object to eating insects and reformulates, which is the modern chapter of a five-hundred-year-old trade.

Textile dyeing, artists' lake pigment, cosmetics, and food colouring at industrial scale. Oaxacan weaving still uses it, and there is a small revival of the traditional trade.

As a colour it is the cool, slightly blue-leaning crimson that reads as formal and institutional: academic, ecclesiastical, military. Compare it to vermilion's orange scarlet and you can feel the difference in temperature doing the work: one is ceremony, the other is alarm. Most brands pick a red without deciding which of those two they want.