How Art Got Its Colors: The Alchemists
Today’s artists are spoiled - for choice that is. Go to any well stocked art supply store and you will be confronted with hundreds, if not thousands, of brilliant and nuanced colors, ready to go. But this is a relatively recent development. Historically, artists had to make their own colors. Though most of the earliest colors such as those found in the Paleolithic cave paintings of Lascaux and Chauvet came from natural mineral sources, the majority of colors, since the time of Ancient Egypt, were manufactured. Egyptian Blue, considered to be the first synthetic pigment (about 2,400 BC) - was created by ‘cooking’ together sand, chalk and copper. It could be created in large quantities, and met the demand for blue that more natural and rarer forms such as turquoise and lapis could not. Later, craftsmen would use trays of vinegar stacked between bricks of lead to corrode the surface making white flakes to produce one of the most prized (and most poisonous) white pigments in all of art history: Lead white. Doing the same with copper plates yielded verdigris, the most vivid green available for painters until the 19th century.
The history and ‘technology’ of artists’ colors is, pun intended, a colorful one. Two of the strangest examples are Mummy brown and Indian yellow. Mummy brown, as the name indicates, was a brown pigment derived from the crushed remains of human and animal mummies. And Indian yellow, a pungent, bright and transparent color, was derived from the urine of cows in India that were force fed mango leaves, to make their urine a bright yellow.
Alchemist. From the Twelve Keys of Basil Valentine. (1599)
According to one of the earliest and most popular manuals for painting, Cennino Cennini’s, Il Libro del Arte from 1390 , by the Middle Ages and the Renaissance, color-making was largely the province of alchemists, the precursors to modern chemists. Though shrouded in tales of madness, magic, and charlatanism, these ‘magicians’ experimented tirelessly with minerals and toxic compounds and were responsible for creating some of the most popular and influential pigments in all of art history. Artists, alchemists, and apothecarists tended to come in families and could often be found in one and the same person: the people supplying the pigments also supplied the tinctures, medicines, and remedies, leading some scholars to note the connection between our word pharmacy and one of the Greek words for color, phármakon .
One of the most well known colors of the alchemists, was red lead – achieved by cooking white lead slowly and uncontained. Also known as minium, in Medieval Latin, it was used extensively in illuminated manuscripts and gave us the word ‘miniature’ as a result, which referred to the ubiquitous use of red rather than the size .
The red sulphur, cabala mineralis, British Library 17th century
But by far the jewel in the crown of Alchemical colors was the creation of vermillion. This bright red, known also as the Dragon’s Blood, was one of the most prized colors in the Middle Ages and the Renaissance, and was made by cooking sulphur and mercury, the main elements of Alchemical theory. Theophilus, in the eleventh century, described the synthesis of vermillion from sulphur and mercury thus:
When you have mixed them carefully, put them into a glass jar. Cover it all over
with clay, block up the mouth so that no fumes can escape, and put it near the fire
to dry. Then bury it in blazing coals and as soon as it begins to get hot, you will
hear a crashing inside, as the mercury unites with the blazing sulphur. When the
noise stops, immediately remove the jar, open it, and take out the pigment. 
This brilliant red fueled the craze for other brilliant hues, which according to art historian Daniel Thompson, transformed the history of art by stimulating the eye and appetite for brighter pigments that came to define the Gothic era and the Renaissance .
Through their quest for the elusive Philosopher’s Stone, shrouded as they were in secrecy and poisonous fumes, they gave artists some of their most valued colors and thereby made a lasting contribution to both material science and visual culture.
 Cennino Cennini (c.1390). Il Libro dell’ Arte. Translated by D. V. Thompson
as The Craftsman’s Handbook (1960). Dover, New York
 Eaton, N. (2013). Colour, Art and Empire: Visual Culture and the Nomadism of Representation (Vol. 12). IB Tauris.
 P. Ball (2001). Bright Earth: The Invention of Colour. Penguin, London
 Hawthorne, J. G., & Smith, C. S. (1963). On Divers Arts: The Foremost Medieval Treatise on Painting, Glassmaking, and Metalwork. Courier Corporation.
 Thompson, D. V. (1956). The materials and techniques of medieval painting (Vol. 327). Courier Corporation.