Here's why:
* Bulls are colorblind: Bulls, like most mammals, are dichromatic, meaning they can only see shades of blue and yellow. They cannot see red.
* It's the movement: Bulls react to movement, not color. The waving of a matador's cape, regardless of its color, triggers the bull's natural instinct to charge.
* The cape's purpose: The red cape is used in bullfighting to distract and control the bull, but it's not the color that makes them angry.
So, the next time you see a bullfight, remember it's not the color of the cape that enrages the bull, but the movement.