Today specifying a color is easy. Whether it's a hex or RGB value, specific paint brand stock number, or a Pantone name, you know exactly how to describe a certain shade. Werner's Nomenclature of Colours is a reprint throwback to a time before photography when words had to substitute for imagery. Penned by an art teacher using Abraham Werner's work, it has vivid names — Berlin blue, sap green — for a variety of shades, alongside color swatches and descriptions of where you could find them in nature. The book proved invaluable in a number of ventures over the years, including in the writings of Charles Darwin, who used it as a reference on his explorations aboard the HMS Beagle.