Two tiles, seemingly different colours from one angle are actually the same colour in different lighting. I don't get it at all. What's the trickery here? Is it the shadowplay? The lights? The tiles? I don't know.
It's MIT's Edward H. Adelson's checker shadow illusion recreated in real life. Viewing the two tiles without the surrounding context would reveal that the two tiles actually are the same colour. Nuts. [BrussPup via The Daily What