Exercise 1 (previous post) demonstrated how the appearance of a colour is affected by its surroundings, The aim of exercise 2 is to experience an afterimage. We are not usually aware of this effect which occurs where colours are adjacent on a flat surface. The eye produces an afterimage of the complementary colour. I found this exercise more difficult than exercise 1 and had to try several times, starring hard at the grey square in the centre and unfocusing my eyes. The results are noted under each square and although some were more noticeable (on the fluorescent yellow and bright orange in the bottom right), all colours produced an afterimage of a discernible hue which related to the complementary colour.