Yves Klein, “The Evolution of Art towards the Immaterial” (1959), in Color, 120-122.
In his piece, Klein describes how color, which is often thought as free of form, is enslaved by lines in order to create realism. The purpose of lines is to “open the eyes of man to the exterior world of matter that surrounds him,” and, in contrast to color, line represents the power of darkness. Blue, however, as Klein describes, is unlike other colors in that it has a feeling of transcendence, and seems to be elevated from reality.