This experiment will trick you into seeing different colours, depending on the speed of the disk. Try it and see whether you see the same colours when it spins at different speeds!
The colour effects change as the speed of the black-white disk changes, and are clearest when the disk is rotating rapidly. Different people can see different colours at the same speed. When the eye is exposed to rapidly alternating black and white areas, the vision cells in the retina react and transmit nerve impulses to the brain. The brain interprets these nerve impulses as different colours.