I saw this on SwissMiss recently and it absolutely blew me away. More than 300 years ago (in 1692), a Dutch artist created an incredible, beautiful, hand-painted book containing 800 pages of guides to colours and hues in watercolours. It was the Pantone Color Guide of the Renaissance, except that only one copy was ever made. The book is held at the Bibliothèque Méjanes in France, and you can see every beautiful page (and practice your centuries-old Dutch) here.