Here's why people saw the dress differently. How does a black and blue dress sometimes appear white and gold? The Brains Blog 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 10 years ago, a simple photograph of a dress sparked a global debate unlike anything seen online before. Posted in 2015, the image caused people to argue intensely over whether the dress