Colours– B.and K. studied carefully the number of colours which usually belongs to different cultures and they established that we can start from a minimum of 2 light and shade, up to a maximum of11. They showed also that if we go on with a gradual definition of several colours, at the end we can get an homogeneous growth in every culture. For example  we choose the colour red after we consider the light and the shade, then green and yellow, up to the orange which is the colour we find in not many cultures.The theory of our two anthropologists was that the known of a larger number of colours depends on the development of every singular culture, but this theory was firmly criticized. Moreover some colours are defined only in association with a natural element(E.G. green like a leaf), in the same way we usually define a red like”rust”.From the relationship between colour and matter getS out two different ways of colours interpretation, that is “colour-quality” in which colours qualify reality and “colour-matter”where the artist makes something new. In the oriental culture colours are”exciting and powerfull”, but forms are”cold and ugly”. Prechristian occidental cultureS, on the other hand pay more and more attention to the form and the use of every structure, but it was very poor of colours: in the ancient greek and in latin there are few words to define a colour and actually those words are punctually related to colours’ dullness or they are associated with a natural element.In general cultures which grow in a AIR of irrationalism love colours and a magnificient example of this theory are byzantine mosaics where colours become precious matter, while generally colour is subordinated to the drawing and then to the form. Impressionists show a new relationship between image and paint and from this dualism, AN antithesis between colour and image spread out. Puntinists and Divisionists used positivist science’discoveries and the Van Gogh cromatic tension corresponds symbolically to the psychological state he had to describe.