“Some scientists (especially physicists) [and] some artists (especially musicians) . . . noticed long ago that a musical sound, for example, provokes an association of a precise color. . . . Stated otherwise, you “hear” the color and you “see” the sound. . . .

YELLOW . . . possesses the special capacity to “ascend” higher and higher and to attain heights unbearable to the eye and the spirit; the sound of trumpet played higher and higher becoming more and more “pointed,” giving pain to the ear and to the spirit. BLUE, with the completely opposite power to “descend” into infinite depths, develops the sounds of the flute (when it is light blue), of the cello (when it has descended farther), of the double bass with its magnificent deep sounds; and in the depths of the organ you “see” the depths of blue. GREEN is well balanced and corresponds to the medium and the attenuated sounds of the violin. When skillfully applied, RED (vermillion) can give the impression of strong drum beats, etc.”

—Wassily Kandinsky, from Concrete Art, 1938.