I know you’ve seen it, whether from TV, social media or a friend pushing their phone into your face and asking “What color is this dress?”
(Disclosure: I only see it as blue and black.)
Don’t worry; there isn’t something wrong with your loved ones who see the dress differently than you. The biological explanation lies in the way in which human eyes have evolved to determine colors under various light conditions, and how those determinations vary from person to person.
Human beings evolved to see in daylight, but daylight changes color. That chromatic axis varies from the pinkish red of dawn, up through the blue-white of noontime, and then back down to reddish twilight. “What’s happening here is your visual system is looking at this thing, and you’re trying to discount the chromatic bias of the daylight axis,” says Bevil Conway, a neuroscientist who studies color and vision at Wellesley College. “So people either discount the blue side, in which case they end up seeing white and gold, or discount the gold side, in which case they end up with blue and black.” (Conway sees blue and orange, somehow.)
Check out this excellent article from Wired analyzing the science behind why people can’t agree on the color of a dress in a poor quality photo.