"The more I think about colour, the more convinced I become that this reflected half-tint is the principle that must predominate, because it is this that gives the true tone, the tone that constitutes the value, the thing that matters in giving life and character to the object. Light, to which the schools teach us to attach equal importance and which they place on the canvas at the same time as the half-tint and shadow, is really only an accident. Without grasping this principle, one cannot understand true colour, I mean the colour that gives the feeling of thickness and depth and of that essential difference that distinguishes one object from another."