Spanning nearly 800 completely handwritten (and painted) pages, Traité des couleurs servant à la peinture à l’eau, was probably the most comprehensive guide to paint and color of its time. According to Medieval book historian Erik Kwakkel who translated part of the introduction, the color book was intended as an educational guide. The irony being there was only a single copy that was probably seen by very few eyes. It’s hard not to compare the hundreds of pages of color to its contemporary equivalent, the Pantone Color Guide, which wouldn’t be published for the first time until 1963.
The entire book is viewable in high resolution here.