Debriefing Part 2

But how do we explain the dress? When the image of this dress first emerged on the Internet, there was a heated debate over whether it was black and blue or white and gold. Some people would even see it as black and blue the first time they viewed it and white and gold another time.

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Why is there so much controversy about the colour of this dress?

Unlike with other colour illusions used in this demonstration, the dress presents ambiguous cues about the lighting in its surroundings. Bright light in the background provides one cue (daylight), while shadows on the dress provide another cue (dim light). People adjust their perception of colour differently depending on whether they believe the object is in daylight or whether it is in dim light.