" To express the love of two lovers by the marriage of two complementary colours, their blending and their contrast, the mysterious vibrations of related tones. To express the thought of a brow by the radiance of a light tone against a dark background. To express hope by some star. Someone's passion by the radiance of the setting sun. That's certainly no realistic trompe l'oeil, but something that really exists, isn't it? "

― Vincent van Gogh , The Letters of Vincent van Gogh