The dress is both blue and black. The photograph of the dress went viral in 2015, and viewers disagreed on whether the dress was blue and black or white and gold. The dress was confirmed as a royal blue "Lace Bodycon Dress" from the retailer, Roman Originals, and a white and gold version was not available at the time. The phenomenon revealed differences in human color perception and became the subject of research by vision scientists. The different interpretations of color are due to how people make assumptions about the illumination conditions in the scene when the photograph was taken. If people assumed the dress was in a shadow, they were much more likely to see it as white and gold because shadows overrepresent blue light.