It’s been almost exactly two years since “the dress” optical illusion and now another conundrum has popped up that plays with our perception of color, as if somebody is celebrating the deep division and fractured relationships caused by the dress’s viral success.
The image of a bright red strawberry tart with a blue-ish tint was shared on Twitter by Akiyoshi Kitaoka, a Japanese professor of psychology, who studies and creates optical illusion artworks. Much to the surprise of your eyes, those strawberries on top are not red at all.
A quick click around on Photograph (or even Microsoft Paint) will show that there are no red pixels in the image at all. Isolating the color of the strawberries will show they are actually a pale greenish gray.
The phenomenon is known as color constancy, much like phenomenon shown off in the dress optical illusion. It’s a feature of the human visual system that leads to the context surrounding the object to influence how we perceive it, in an attempt to ensure that the perceived color of an object remains uniform across different light sources. In this photograph of the strawberries, it becomes apparent there’s a blue tint over the image. Our perception makes us assume we are seeing the strawberries under this blue-tint and tries to account for it.
Bevil Conway, an expert on visual perception from the National Eye Institute, explained to Motherboard: “You brain says, ‘the light source that I’m viewing these strawberries under has some blue component to it, so I’m going to subtract that automatically from every pixel.’ And when you take gray pixels and subtract out this blue bias, you end up with red.”
Conway added that it also helps we closely associate strawberries with the color of red, so we subconsciously trick ourselves into perceiving this.
Thankfully, unlike the dress, at least we can all agree we are seeing the same color.