Matisse and Derain painted portraits of each other while staying at the port of Collioure in the south of France. Using vivid, apparently arbitrary, colours, Matisse has captured the sensation of sunlight striking the sitter's face and casting a heavy shadow down one side. He has also tried to create a dynamic but balanced relationship between complementary colours, such as blue and orange, red and green. Complementary colours 'complete' each other: they are at their most intense when placed together. Matisse adjusted his colours to obtain the maximum intensity. This non-naturalistic use of colour can be seen as a radical development of certain aspects of Impressionist art, and it led the critics to dub Matisse a 'fauve' (wild beast).