I expect it was "done" mainly to document the author's interest in pigment exploration and "used" by his students.

Want to learn some state of the art watercolor technique in the late 1600's? Go study under A. Boogert for a few years. Especially valuable because he has created a this massive reference of colors, A solid foundation for an esoteric subject.

I bet every student of his left with their personally created abridged copy containing the most useful colors. to be passed on to their students.