If your eyes follow the movement of the rotating pink dot, you will only see one color, pink. However, if you stare at the black "+" in the center, the moving dot turns to green. Now, concentrate on the black "+" in the center of the picture. After a short period, all the pink dots will slowly disappear, and you will only see a green dot rotating. It's amazing how our brain works. There really is no green dot, and the pink ones really don't disappear. _________________