Ten years ago, a photo of a dress posted on Tumblr sparked a massive debate: was it blue and black or white and gold? Millions argued online, and even celebrities joined in. Scientists later explained ELI5:Why does this dress appear white gold to some people and black blue to others? : r explainlikeimfive Optical illusion renews blue and black dress debate nine years on Express.co.uk The Science Behind the Dress Illusion Eyepic Eye Care Why nobody could agree on the color of that dress on X Is That Dress White and Gold or Blue and Black? The New York Times