The aim of my thesis on colour theories of the Enlightenment and their influence on avant-garde art, was to show the different approaches of modernist artists to the tradition of colour research at the turn of the 18th and 19th centuries. The starting point of the text is the critical analysis of Newton's colour theory, which was conducted by Goethe. The emphasis on empirical experience, which laid the basis of this new science, had a big influence on the work of painter and friend Philipp Otto Runge. The synesthetic theory of George Field also shows an interesting connection to the work of the fin de siècle. The symbolist colour theories are discussed because of their importance to the artists who opened the path to abstract painting, for example Frantisek Kupka, Pieter Mondrian and Vasilij Kandinskij. A chapter was also dedicated to Robert Delaunay, who developed a very sophisticated explanation of how to represent movement in colour contrasts. The American synchronists, who were very proud of their specific artistic movement, were also inspired by Orphism. An important part of the thesis is the focus on Bauhaus artists. Some of them were influenced by the painter Adolf Hölzel, a native of Olmütz in Moravia, who was very interested in Goethe's Farbenlehre. Johannes Itten, a student of Goethe's, was the...