The iconic red London bus has a long history. In 1907 at a time when there was fierce competition for passengers, and route numbers had only just been introduced, operators still used a variety of colours to indicate where the bus was going. The largest operator, London General Omnibus Company, decided to make its buses stand out. It chose a spoked wheel as a symbol and the colour red for all its vehicles. When London Transport was eventually formed as a single company in 1933, red was already the predominant colour, so all buses in the Greater London area became red.
Answered by Caroline Warhurst, London Transport Museum.