"[Johannes] Itten wrote in 1916: "Form is also color. Without color there is no form. Form and color are one." It never occurred to me to make a three dimensional work without color. I took Itten's premise, which I had not read, for granted...Color is like material. It is one way or another, but it obdurately exists. Its existence as it is the main fact and not what it might mean, which may be nothing...Color, like material, is what art is made from. It alone is not art. Itten confused the components for the whole. Other than the specturm, there is no pure color...I like the color (red) and I like the quality of Cadmium Red Light. (It has) the right value for a three-dimensional object. If you paint something black or any dark color, you can't tell what its edges are like. If you paint it white, it seems small and purist. And the red, other than a gray of that value, seems to be the only color that really makes an object sharp and defines its contours and angles"
(Donald Judd, 'Some Aspects of Color in General and Red and Black in Particular' 1993 and as cited in John Coplans, Donald Judd, Pasadena 1971, p. 25.)