So glaring lights that spread light pollution are OK, as long as they are not mercury vapor. Doesn't make a lot of sense.
Around where I live, there are thousands of mercury vapor security lights and NEMAs in use. The hillsides are dotted with little white lights from them. However, the sky glow is not blue-green-white from them. It's gold from the thousands of high wattage HPS street and parking lot lights, many of which I think could be down-rated and still do an adequate job of lighting their areas.