A style of Abstract Expressionist painting that emerged in New York City during the 1940s and 1950s. Color field painting is characterized by large fields of saturated color spread across or stained into the canvas, creating a flat picture plane. In comparison to action painting, the style places less emphasis on gestural brushwork. Initially coined by critic Clement Greenberg, the term was first applied to the work of three American painters: Mark Rothko, Barnett Newman and Clyfford Still.  Starting around 1960, a more purely abstract form of color field painting emerged in the work of Helen Frankenthaler, Kenneth Noland and Morris Louis. Web resource here.

Morris Louis. Tet. Magna on Canvas. 1958. Whitney Museum of American Art.