Picture a classic bullfight: a matador poised with a vivid red cape, the muleta, taunting the massive beast across from him. The crowd holds its breath. The bull snorts, lowers its head, and charges furiously. To many spectators, it seems obvious: the bull sees red, becomes enraged, and reacts.

But, scientifically, that narrative doesn’t hold up.

Despite what tradition and pop culture might suggest, bulls do not “hate” the colour red. In fact, they can’t even see red in the way humans do. The idea that red provokes aggression in bulls is a long-standing myth—one scientists, zoologists, and researchers across fields have repeatedly debunked. What actually causes a bull to charge has less to do with colour and far more to do with movement, fear, and instinct.

The science of bull vision

This misunderstanding stems from how bulls, and cattle in general, see the world. Unlike humans, who have trichromatic vision (three types of colour receptors in our eyes), bulls have dichromatic vision.…