A three-color confetti illusion with spheres, which appear to be yellowish, reddish, and purpleish but in fact have exactly the same light-brown base color (RGB 255,188,144). Shrinking the image increases the effect. Original png file is at https://t.co/6r2PMbLMJc. pic.twitter.com/ro1zpVxLm2

— David Novick (@NovickProf) June 14, 2019