This poster or print of my painting, The Grain Mill, is available at http://www.zazzle.com/arlenebabadartist. A postcard of this painting won Zazzle's Today's Best Award.
After image of colours is an optical occurrence. Consider the complementary pair of orange and blue colours. Stare at an orange shape for several seconds and then look at a white shape. You will see the complement, blue, on the white shape. The blue will be lighter but it will also mirror the shape of the orange colour. Stare at an orange shape and then look at a second blue shape. You will see a brighter blue mirroring the original orange shape. This observable fact is called after image. Artists can use this event in their paintings.