Pôster Turning Blue Optical Illusion

There exist no blue color in this image whatsoever. For a better view the magnifier (View a larger image) should be used. Now focusing strictly on the black star in the center of the image, counting to 50 or more (just as an example) will make slowly the four circles diminish in the field of vision. At this moment, moving slowly the eyes in all directions will create a dance of blue crescents inside the circles, which finally turn bright light blue. The longer the observation, the deeper the light blue color. (Please note: Images of similar colors in this category "Creating Illusory Colors", should not be watched one after the other, otherwise the to-be-created color will be present from the start. It is better to wait a certain period of time - like 15 minutes - before viewing another image with the same colors.)