Keep looking at the center of the blue flower. After a short time, whenever the gray background appears, you will instead see the picture in its original colors, a yellow flower with purple flowers in the background. For comparison, look here to see the original "Complementary Colors" image: https://addons.mozilla.org/en-US/firefox/addon/complementary-colors/#id=312343 To rate or comment, login here: https://addons.mozilla.org/en-US/firefox/addon/complementary-colors-illusi/#id=373594 See all my personas here: https://addons.mozilla.org/en-US/firefox/collections/BrianZ/personas/ (optical illusion, yellow, purple, gray, inverse, color negative) (c) 2012 BrianZ All Rights Reserved