This blew my mind.
“Traité des couleurs servant à la peinture à l’eau” is an 800-page color guide, written in 1692 by an artist known as A. Boogert. The book describes and shows in detail how to use and mix colors. I can’t even begin to imagine how long this took to make, and the fact that the colors are still so vibrant is astonishing. This is a work of art, and I would bet that most of what is in this book is still relevant today.
It’s also great to see that Boogert was also educated in grid systems. Have a look at how those swatches are organized.
A hi-res gallery of the entire book is available here