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 Why the world couldn't agree on the color of 'the dress' New York Post How "The Dress" Became an Illusion Unlike Any Other Scientific American The actual dress was black and blue. The confusion came from how lighting and color perception tricked people's brains, making some see it as white and gold. It became a viral example