 The models that can be used must be homologated previously for this function by the local authorities, and they are always four-door sedans or minivans.Regarding the livery, each town and city designates the colour of their taxis, but in the overwhelming majority, it is white, usually with some kind of colour detail and/or local symbol on the doors.For example, in Madrid (and also in Almería), taxicabs are white with a red diagonal stripe going through the front doors; in Seville, they are white with a diagonal yellow stripe down the rear doors; in Bilbao, white with a horizontal red stripe on the front doors, etc.