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 The dress is black & blue, but here's why you can't tell TJ Kelly Is the dress blue black or white gold? Body Worlds Amsterdam The white gold blue black Internet #dressgate: Stages of certainty,confusion, horror, and acceptance Rage Against The Minivan This explains how the blue black white gold dress illusion was possible. But it doesn't explain why some people saw it one way and some saw it the other, and no one seemed to see