The chief aim of color should be to serve expression as well as possible. I put down my colors without a preconceived plan. If at the first step and perhaps without my being conscious of it one tone has particularly pleased me, more often then not when the picture is finished, I will notice that I have respected this tone while I have progressively altered and transformed the others. I discover the quality of colors in a purely instinctive way.

p. 412 - 'Notes d'un Peintre', (Notes of a Painter), H. Matisse (1908)