By 1949 Rothko had introduced a compositional format that he would continue to develop throughout his career. Comprised of several vertically aligned rectangular forms set within a colored field, Rothko’s “image” lent itself to a remarkable diversity of appearances. In these works, large scale, open structure and thin layers of color combine to convey the impression of a shallow pictorial space. Color, for which Rothko’s work is perhaps most celebrated, here attains an unprecedented luminosity. His classic paintings of the 1950s are characterized by expanding dimensions and an increasingly simplified use of form, brilliant hues, and broad, thin washes of color. In his large floating rectangles of color, which seem to engulf the spectator, he explored with a rare mastery of nuance the expressive potential of color contrasts and modulations.