Look at the horizontal bar in the middle. Is it all one solid shade of gray? Or are there darker and lighter parts?

Gray rectangle in front of a black-to-white gradient background.

Show me!

It’s just one shade of gray!

Check out another illusion like this one!

Look at the two dinosaurs. Are both the same color, or are they different?

Two identical dinosaurs on a yellow-to-purple gradient background.

Show me!

They’re the same!

Your brain is overruling your eyes again, trying to adjust for what appear to be differences in lighting.

The dinosaur on the lighter background looks darker than it really is. And the dinosaur on the darker background looks lighter than it really is. Take out the background shading, and you’ll see that the dinosaurs are identical!

Next, find out how you see colors that aren’t even there. Take a look!