12.—(1) A public service vehicle which is more than 2½ metres in height may carry on the foremost and topmost part of the vehicle not less than two nor more than 5 lamps each showing, when lit, a diffused light of a colour approved by the Registrar.
(2) The lamps referred to in paragraph (1) shall be lit only during the hours of darkness when the vehicle is carrying passengers for hire or reward.