The pigments that were the traditional base ingredients of paints were gradually discovered by humankind over many millennia. As recently as the fifteenth century, it was still extremely difficult to find lapis lazuli, the blue mineral that was the main ingredient in ultramarine paint. The great painter Jan van Eyck would only include blue in a portrait if the client paid extra, and when he did it would be in small quantities, unblended with other colours, and highlighted to emphasize its use. This is also the reason why Jesus’s mother Mary was traditionally depicted swathed in blue, to emphasize her high status.
Lapis lazuli was in use at least 6,500 years ago, and was highly valued in the early civilizations of Mesopotamia, Egypt and China. There are still lapis lazuli mines in Badakhshan, a remote, mountainous region of Afghanistan – they have been continuously in existence since at least 700 BC, when they were part of a country known as Bactria.
Purple was also a traditionally expensive colour. Tyrian Purple was a pigment made from the mucus of the Murex snail. It was in use as a fabric dye in about 1200 BC. Green paint, which was in use from prehistory, was also relatively rare, being primarily derived from the clay minerals of celadonite and glauconite.
However, there were some colours that were in plentiful supply from the early history of humankind. Carbon black can be made from charred bones or wood; yellow and red come from iron oxides; brown, in a variety of shades, can be made from iron and manganese oxides; and white can be made either from chalk or from animal bones. All of these pigments could be used to colour human skin or the walls of caves, either by directly applying them or by mixing them with animal fat and thus making a primitive paint mixture. The earliest evidence we have of painting comes from at least 350,000 years ago – equipment for grinding paint and pigments was found by archaeologists in a cave at Twin Rivers, which is close to Lusaka in modern-day Zambia.