In 2015, a photograph of a dress went viral, dividing viewers over whether its colors were blue and black or white and gold. This optical illusion highlighted differences in human color Proof the Dress Is Blue PS Tech Light Blue Satin Long Sleeve Maxi Dress Large Azazie Norah Dusty Blue Chiffon Bridesmaid Dresses Azazie This explains how the blue black white gold dress illusion was possible. But it doesn't explain why some people saw it one way and some saw it the other, and no one seemed to see