“The barber’s pole reflects a time when barbers not only cut hair, but performed medical operations such as bloodletting. Prior to the barber pole, barbers would place bowls of blood in their window to advertise their bloodletting capabilities, though that act was prohibited by a 1307 law in London. Hence, the barber’s pole was born, and it has remained a popular symbol ever since.”

“The look of the barber pole is linked to bloodletting, with red representing blood and white representing the bandages used to stem the bleeding. The pole itself is said to symbolize the stick that a patient squeezed to make the veins in his arm stand out more prominently for the procedure. In Europe, barber poles traditionally are red and white, while in America, the poles are red, white and blue. One theory holds that blue is symbolic of the veins cut during bloodletting, while another interpretation suggests blue was added to the pole as a show of patriotism and a nod to the nation’s flag.”

Source: https://www.history.com/news/why-are-barber-poles-red-white-and-blue

Source: https://estelarbarbers.com/barber-pole-history-and-significance-explained/

Source: https://interestingfacts.com/symbol-meanings/