You're reporting something very unusual. Usually, the local officials (and local boaters) treat an established mooring field as if it's a Special Anchorage (whether or not it's designated officially on the charts). What I'm thinking is "Who pissed in the local DNR's cornflakes?"Thanks @Kings Gambit - I posted without directly referring to the COLREGs so used an incorrect term. The point I wanted to make is that you will most likely have to have an all around white light (anchor light) if you are on a mooring, whether you set it up yourself or you are at a municipal or club mooring field. Being in a mooring field doesn not negate the requirement. A mooring is nothing more than a "fixed anchor point" as far as the COLREGs are concerned.
We got into this when the SC DNR came by and notified our club that they would start writing citations for not having all around white lights at night. We investigaged and sure enough he was correct. As a secondary issue, we are immediatly adjacent to the ICW and if there were a collision at night I"m not sure the moored boat would not be cited and deemed at least partially responsible for the collsion.
A 20-watt solar panel, cheap solar regulator, and LED anchor light can address that issue.
PS - I wonder if it's difficult to get the Corp of Engineers to establish the designated area officially?