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 perception ELI5:Why does this dress appear white gold to some people and black blue to others? : r explainlikeimfive Here's why people saw the dress differently. Blue Gold Formal Metallic Paisley Print Gown Barbie Fashion Sheer Sleeves Dress eBay The white and gold dress, and the illusion of free will Felipe Contreras