16 GCA § 3202: Spot Lamps.

(a) A motor vehicle or motorcycle may be equipped with not more than one (1) spot lamp and such spot lamp shall be so aimed and used when lighted, upon approaching another vehicle, that no part of the high intensity portion of the beam will be directed to the left of the prolongation of the extreme left side of the vehicle nor for a distance greater than one hundred (100) feet ahead of the vehicle.

(b) No person shall operate or move any vehicle upon the public highways bearing or displaying a lighted red or blue lamp or light, other than a rear lamp as described in this Chapter, unless such vehicle be an ambulance, a vehicle attached to the Guam Police Department, or to a military law enforcing agency or such vehicles authorized to carry such red or blue lamp by the Chief of Police.

(c) All automobiles or motorcycles used or authorized to be used by the Guam Police Department as police vehicles shall be equipped with blue revolving or flashing lights.