This is a picture of pink dots that disappear in rotation.
1) If your eyes follow the movement of the rotating pink dot, the dots will remain its true colour – pink.
2) If you concentrate at the black ‘+’ in the centre, the moving dot turns to green.
3) If you continue concentrating on the black ’ + ’ in the centre of the picture . The pink dots will slowly disappear, and you will only see a single green dot rotating.
Enjoy : )