illusory yellow pic.twitter.com/xIxX6eHMcq— Akiyoshi Kitaoka (@AkiyoshiKitaoka) November 30, 2023
Japanese experimental psychologist Akiyoshi Kitaoka (previously at Neatorama) consistently fools our eyes with his optical illusions. In this graphic, you see three circles: cyan, magenta, and yellow. But there is no yellow. You can zoom in or use an eyedropper tool to check, but Nicolas Jacob already did that for us.
What we perceive as a yellow circle are white stripes, the same as in the background of the graphic. What's different is that the yellow circle area is made up of black stripes instead of the blue stripes that the rest of the graphic has. In subtractive color mixing, the perception of color is produced by the absorption of light by other colors. Yellow is produced by the absence of blue, so the black and white stripes on a field that is otherwise blue-striped produces the illusion of yellow. Notice the green area of overlap is made of cyan and black. Color is in the eye of the beholder. Or is it? -via Boing Boing