We know that strawberries are red, or at least they should be, so that's what we see. Professor of Psychology Akiyoshi Kitaoka (previously at Neatorama) created this image of strawberries that contains no red pixels at all. This is an example of color correction in our brains. We essentially filter out colors that make no sense to us in order to see things as they should be. Carson Mell isolated the colors found in the strawberries, and none of them are red.
@social_brains I isolated a few of the colors that appear most "red" in the strawberries and put them on the white background to the right. pic.twitter.com/GJJ9PJqNxt— Carson Mell (@carsonmell) February 28, 2017
It's easier to see the color of the berries in this image. Cover the strawberries with your hand to get a better look at the color bar at the bottom.
@carsonmell @social_brains I drew three rectangles on top to also show the effect. pic.twitter.com/PaSxflmGJv— Tim Hutton (@_tim_hutton_) February 28, 2017
An article at Motherboard explains what's going on in your brain when you see a picture like this.
"If you imagine walking around outside under a blue sky, that blueness is, in some sense, color-contaminating everything you see," explained Bevil Conway, an expert on visual perception from the National Eye Institute. "If you take a red apple outside under a blue sky, there are more blue wavelengths entering your eye. If you take the apple inside under a fluorescent or incandescent light without that same bias, the pigments in the apple are exactly the same but because the spectral content of the light source is different, the spectrum entering your eye that's reflected off the object is different."
Since all this color contamination from light sources isn't really useful (it would be super confusing if a ripe banana looked yellow in the morning but green at midday, for example), our brains have evolved to color correct. It allows the colors we see to look the same no matter the lighting.
(Image credit: Akiyoshi Kitaoka)