“Bulls are enraged by the color red.”

The enduring image of a bull charging a matador's vibrant red cape has cemented a common belief that the color itself is an infuriating sight for these powerful animals. This misconception largely originates from the dramatic spectacle of Spanish bullfighting. Over centuries, the red cape, known as a muleta, became a traditional prop in the arena, leading spectators to naturally associate the bull's aggressive charge with the crimson fabric. However, the choice of red for the cape was primarily for aesthetic reasons and practicality for the human audience, such as masking bloodstains and enhancing the visual drama of the fight.

Scientific evidence clearly busts this myth. Bulls, like most cattle, are dichromats, meaning their eyes possess only two types of cone cells for detecting color, unlike humans who have three. This makes bulls functionally colorblind to red and green. To a bull, the bright red cape appears as a dull yellowish-gray or brownish-gray hue. Therefore, the color red holds no special power to enrage them.

What actually provokes a bull during a bullfight is the movement of the cape and the matador, not its color. Bulls react instinctively to sudden, aggressive motions, perceived threats, and contrasts in their environment. Studies have demonstrated that bulls will charge at any moving object, regardless of its color. The high-stress environment of the arena, filled with noise, confinement, and the matador's erratic movements, further agitates the animal, triggering its natural fight-or-flight response. The widespread belief persists due to the strong visual narrative of bullfighting, reinforced by popular culture in movies and cartoons, and the common association of the color red with anger and danger.