Are bulls enraged by the colour red?

Ekpreet Sahota

Have you ever heard of the saying “like a red rag to a bull”? It means to be something that causes anger or annoyance. This saying is based on the practice of bullfighting, which involves a Matador (the bullfighter) waving a Muleta (a red cape) in front of a bull. This causes the bull to angrily respond and charge at the Matador. The colour red is commonly associated with anger and aggressiveness, so it’s a popular belief that a Muleta enrages the bull simply because of its red colour – but is this true?

The answer is no. In fact, bulls are actually colour-blind to the colour red!

It is actually the aggressive whipping of the Muleta by the Matador which irritates the bull. This causes the bull’s ‘Fight or Flight’ response to become activated.

What is the Fight or Flight response?

The Fight or Flight response (also known as the ‘stress’ response) is a reaction that happens in response to a situation where you feel as if you’re in danger or are going to be harmed. Your brain will assess the situation and decide whether or not you are really in danger. If you are in danger, your brain will send signals to your glands to release certain hormones. Hormones are small chemical messengers which travel through the blood system to different parts of the body to tell them what to do. In the Fight or Flight response, the hormone adrenaline is released from the adrenal gland, in order to prepare the body for survival.

Changes in the body include:

  • Increased Heart Rate and Breathing Rate – provides the body with more oxygen and energy so muscles can become rapidly activated
  • Dilated Pupils – lets more light into the eyes to allow better vision of the surroundings
  • Sweating – cools down the body so it doesn’t overheat

Your body will then be prepared to either:

  • FIGHT – attack and deal with the threat


  • FLIGHT – escape from the threat to safety

Now I want you to imagine the bull in this situation…

The bull is surrounded by thousands of people in the audience shouting and creating a lot of noise, causing the bull to become irritated and confused. As the bull scans its surroundings, its brain will register that it’s not in a calm and safe environment. Once the Matador aggressively whips the Muleta, the bull’s brain will associate that sudden movement with danger. This will trigger the Fight or Flight response and the release of adrenaline, causing the bull to charge at and attack the Matador in order to get rid of the threat and survive.

In case you still don’t believe me, the red Muleta is traditionally only used in the third and final round of bullfighting. In the first and second round, the Matador uses a different coloured cape (usually pink or yellow), and the bull still attacks!

So, it’s all in the movement of the cape and not the colour!