Regulation 176(1) applies.
Reg 176. Identification lamps
(1) A bus or a goods vehicle, the gross vehicle mass of which exceeds 3 500 kilograms, and which is not a motor vehicle referred to in subregulation (2), (3) or (5), may be fitted above the windscreen with two or more identification lamps and each such lamp shall—
(a) not exceed a capacity of 21 Watts;
(b) be visible from directly in front of the motor vehicle to which it is fitted; and
(c) emit a green or amber light.
Alta Swanepoel and Associates CC
— Arrive Alive (@_ArriveAlive) March 7, 2017