Any motor vehicle may be equipped with fog lights, not more than two of which can be illuminated at any time, one or two auxiliary driving lights if so equipped by the manufacturer, two daytime running lights, two side lights of not more than six candlepower or 75.42 lumens, an interior light or lights of not more than 15 candlepower or 188.55 lumens each, and signal lights. The provision of this section limiting interior lights to no more than 15 candlepower or 188.55 lumens shall not apply to (i) alternating, blinking, or flashing colored emergency lights mounted inside law-enforcement motor vehicles which may otherwise legally be equipped with such colored emergency lights, or (ii) flashing shielded red or red and white lights, authorized under § 46.2-1024, mounted inside vehicles owned or used by (a) members of volunteer fire companies or volunteer emergency medical services agencies, (b) professional firefighters, or (c) police chaplains. A vehicle equipped with lighting devices as authorized in this section shall be operated by a police chaplain only if he has successfully completed a course of training in the safe operation of a motor vehicle under emergency conditions and a certificate attesting to such successful completion, signed by the course instructor, is carried at all times in the vehicle when operated by the police chaplain to whom the certificate applies. Unless such lighting device (i) is both covered and unlit or (ii) has a clear lens, any reflector in such lighting device is clear, and such lighting device is unlit, no motor vehicle that is equipped with any lighting device other than lights required or permitted in this article, required or approved by the Superintendent, or required by the federal Department of Transportation shall be operated on any highway in the Commonwealth. Nothing in this section shall permit any vehicle, not otherwise authorized, to be equipped with colored emergency lights, whether blinking or steady-burning.