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 How does a black and blue dress sometimes appear white and gold? The Brains Blog Exploring Color Constancy: The Dress Phenomenon Explained The science behind 'the dress' White and gold or blue and black what colour is the dress? An eyewitness gives a definitive answer The Independent The Independent What I never understood was if some folk saw the original dress as white gold & some saw it as black blue then how do side by side images like this exist showing them as two