660-669: Chemical Engineering. Chromotopia, by David Coles

 Most beginning artists quickly realize that they need to know how to use color. For that, I refer you to the classic and beautiful Interaction of Color (also available as an iPad app!) for which colors to select, and to Color by Betty Edwards for how to create the colors you choose out of a 15-tube palette. Edwards nods to the chemistry of color when she talks about the limitations of color mixing and the behavioral differences between all the hues labelled "blue." But if all that information leaves you wondering, "But why? Why are there so many blues (or greens, or yellows, or...), and why do they have such odd names, and why are they all different kinds of prices, and why do they not do as I expected when I mix them?" -- well, for those kinds of questions, Coles is your man.

Color is chemistry, as it turns out. Well, and physics-- the physics of light. Chromotopia is everything you ever wanted to know about how color is made. Turns out paint-- or dye, or any kind of color-- is not made out of, I dunno, color, or magic light-refracting science. It's all made out of stuff. Everything from bugs to plants to rocks to poop to rust has been ground up, boiled, burned, corroded and/or infused to make pigments that, when added to oil or egg or water, become paint or dye. They are chemicals that react with other chemicals, sometimes with unexpected results--ultramarine can become pink when heated; cobalt can react with other additives to become green, violet or yellow. 

From Egyptian Ceramic Art, by Henry Wallis

People have been making pigments out of whatever they had around ever since the cave paintings, and the whole time they've been trying to solve three problems: expense, toxicity and lightfastness. Expense was the first challenge. Colors that weren't made of dirt and smoke and wood were typically made of ground-up gemstones or of organic matter than had to be highly concentrated, like indigo or tyrian purple. The Egyptians were the first to synthesize a brilliant color, the blue of faience.

However, both natural and synthetic pigments can be dangerous. Vermilion was made with mercury, which was mined by slaves who typically were killed by the work. Lead white has been used since ancient times, but, of course, was recently discovered to be highly toxic. Emerald green is made of arsenic, which you would think would be a dealbreaker, but, no-- It was available for sale until 1960! 

Lightfastness may seem like a trivial problem compared to the others, but any artist who has worked hard on a watercolor only to find its blues and greens disappearing in sunlight will agree that it must be addressed. The impermanence of color has affected our understanding of art history, too-- many medieval paintings seem to represent grass and trees as blue only because the greens they could access were unstable. And the Greeks did not choose to live in a rarified, Instagram-ready all-white world-- ultraviolet light studies have revealed that they painted their statues in vibrant, lifelike colors. Therefore, advances in lightfastness are just as welcome as those in affordability and safety.

PS-- if you want to make your own colors, there are five recipes at the back of the book. However, this book is not really designed to make you a better painter; it will just help you develop your respect for your materials!