You've Probably Seen These 5 Color Illusions, But You Haven't Seen These Explanations

In this illusion, boxes A and B are actually the exact same color. 

Here you can see what they really look like. This is because of color constancy. Cone cells, which help you to see color, cause you to see them differently because of the way your brain perceives the shadow that "B" is under. 

This another example of color constancy. The inner squares appear to be different colors, but they're actually the same. Both squares reflect the same amount of light but look different because of the squares that outline them. 

You can see dark spots at the intersection of each line, but if you stare long enough, the intersections are white. Scientists believe this is because of lateral inhibition theory. The theory states that when your brain interprets signals from photoreceptors, active receptors effect the activity of neighboring cells, which causes changes in the white/black contrast. 

This is another example of lateral inhibition theory. Both parts of this illusion are the same color. If you cover the fold between them, you'll be able to see it. 

The red stripes on both sides of this image are the same color, but the right side seems darker because of context. Scientists think this could be another example of lateral inhibition theory, but aren't sure.