The dress was a 2015 online viral phenomenon centred on a photograph of a dress. Viewers disagreed on whether the dress was blue and black, or white and gold : r wikipedia Optical illusion renews blue and black dress debate nine years on Express.co.uk What colour is the dress? Explained : r interesting The Dress is now a Halloween costume 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