Benham’s top is one of many classic examples of subjective colors. You should be able to see faint colors in the positions of the arcs of the black-and-white spinning circular disk. The saturation of the perceived colors can be adjusted by changing the spinning speed with the slider control. Different sections of the arcs produce different colors. When the disk spins clockwise, the perceived colors range from yellowish for the inner arcs to bluish for the outer arcs. This order of the perceived colors reverses if the disk spins counterclockwise.