Traité des couleurs servant à la peinture à l’eau is a book by the artist A. Boogert, published in 1692. On 800 hand-written pages in Dutch, he catalogued every watercolor that could be prepared with the then existing paint technology. He also gave instructions for changing the hue by adding one, two or more parts of water. Unfortunately only a single copy remains preserved, it is kept in the Bibliothèque Méjanes in Aix-en-Provence, France.