Vier verbundene Gruppen , by richard paul lohse , 1966 , abstract , Concretism style , Font, Line, Violet, Rectangle
A blue, purple, and yellow square with the letter H in the middle.
A square is composed of blue, purple, and yellow blocks. The purple block is the letter "H" and the yellow block is a square. The blue block is on the top and the purple block on the bottom. The square has a white border around it.