 In London, the volume of traffic has led to restrictions upon the national scheme in some areas with local colour schemes used to restrict standard concessions to local residents, for example the permits are green in Camden, white in Westminster, purple in Kensington and Chelsea, and red in the City of London.In these cities and boroughs special rules and parking spaces are provided for Blue Badge holders.Similar local schemes operate in other large towns or cities in the UK, for example Norwich operates a 'green badge scheme'.