Technology makes my job fairly easy—but I often hear legends of long nights spent in the studio assembling comps without computers.
One tool that I reference almost daily is the Pantone Color Guide, which was published for the first time in 1963.
But over 250 years earlier, in 1692, a Dutch artist, known as A. Boogert, wrote Traité des couleurs servant à la peinture à l’eau—a book about mixing watercolors. The book explained (in Dutch) how to create certain hues and change the tone by adding one, two, or three parts of water.
This is a simple idea, that became a book of 800 completely handwritten (and painted) pages of complex detail. The scope of this project is rather unfathomable, and had to have been the most comprehensive guide to color of its time. Written as an educational guide, there was only ever a single copy.
You can read more on This is Colossal or view A. Boogert's entire book here.