In 1692 a Dutch artist, known only as A. Boogert, put together a book about mixing watercolours. With helpful visual references and explanations of how to create each hue for painting, the 800-page index is incredibly detailed and certainly ahead of its time.
Entitled Traité des Couleurs Servant à la Peinture à l’Eau, it was apparently intended as an educational guide, but there was just one single copy so it's unlikely many got the chance to see it. When you look at the pages of colour, with helpful rectangle references, you can't help but compare the book to its contemporary equivalent – the Pantone Colour Guide, which was first published in 1963.
If you want to see the entire book for yourself, then you can see it online in high resolution. The actual book is currently stored at the Bibliothèque Méjanes in Aix-en-Provence, France.