It's no secret that putting various colors together makes them look different. Put off-white next to black, and it looks completely bright. But did you know that, with the Munker Illusion, you can make something change color completely, right in front of your eyes?
The Munker Illusion is one of those illusions that works, even when you know the trick. Your brain knows that it's making a mistake, but that doesn't matter. You still see something that you know can't be right.
It's a chromatic illusion, which means it relies on your brain's way of seeing color. As illusions go, it's one of the simplest ones out there. It has three elements: a background color, a colored shape, and bars that go over the entire picture in a third color. Generally the bars and the background will be at opposite ends of the spectrum — either very light or very dark. The shape will be the same color. All that will vary is in one picture, the background will be bright, and the bars will be dark, while in another, the background will be dark and the bars bright. The shape's color won't actually change, but it will appear entirely different.io9 have a great article about this illusion.