OnThisDay Ten years ago a great dress color debate was born! The dress became a viral phenomenon in 2015 with social media torn on whether the dress was blue and black or ELI5:Why does this dress appear white gold to some people and black blue to others? : r explainlikeimfive 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 The medical truth behind #TheDress. And yes, it makes sense.