Van Gogh's Secrets: A Unified Theory of Color/Music

This book shows the reasons why different colors are harmonious or are discordant to one another.

It is not the only method of creating harmony in paintings. It is, however, the simplest and the broadest way of achieving it.

It is also a universal theory in that it unifies color and note harmony into one harmonic theory. That is, of course, inasmuch as half of the theory necessarily uses light while the other half necessarily uses time for a medium.