If your eyes follow the movement of the rotating pink dot,the dots will remain only 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 only a single green dot rotating.

Ism't it amazing how our brain works?

We don't always see what we think we see.