Colour was a very important problem in the whole work of Stanisław Ignacy Witkiewicz. Not only a whole chapter of his basic theoretical work Nowe formy w malarstwie (New Forms in Painting, published 1919) was devoted to that but the artist also examined his theory in practice executing many paintings presenting his ideas (e.g. Self-portrait, 1913, Portrait of Feliks Lewiński, 1917, Portrait of Maria Witkiewiczowa, 1918 and many others). A base for that was a harmony of complementary colours: green and red, blue and orange, violet and yellow. Many theorists before Witkacy were interested in that: Wolfgang Goethe, Philip Otto Runge, Wassili Kandinsky. The artist didn’t mention them in his deliberations but a psychologist, Hermann Ebinghaus (G...