As the Minimalist Donald Judd progressed in his career, he tended to increasingly incorporate colour into his work. His forms became more complex, though still composed of fundamental elements. In the huge rectangular object Untitled, Judd bolted together yellow, red, blue and turquoise panels of enamelled aluminium. The individual components are shaped like a shoe-box top, identical in form. Each element has only one colour. Shadow and light cause slight variations in each constituent part because of its shape. Judd wanted to combine varied strong colours without the whole object being harmonious or inharmonious. With this work it is clear that Judd was gradually more fascinated by composition, although his aversion to illusion remained. As he progressed as an artist, Judd explored new possibilities while still using the same basic forms that interested him in the 1960s.