Does A Red Flag Agitate A Bull?

It is the general belief that a red flag agitates a bull and makes it angry causing t to attack and as such a bull fighter requires a red cloth and a bright red cap. The actual fact is that the bull will become angry and attack no matter what color cloth the bull fighter waves since a bull is color blind. The reason is the movement of the cloth and not the color. anything waved in front of a bull will excite it.