I think they should basically make certain color lights for certain emergency vehicles. Say blue for police red for fire and so forth. It seems most states have their own rules about it. We had a volunteer firemen in a village 5 miles from here that ran blue lights for the longest time because they were all he had when he lived in the North East, they ended up making him get them changed to red. In Columbus, the service trucks, like on the highway, have red lights on them. The mix in light colors among areas really can confuse drivers, just as unmarked police cars in areas that allow them to do traffic enforcement. Id have a hard time stopping for an unmarked car unless I called in to the dispatch number to have them confirm with their units if they were trying to make a stop on me, you just never know what the criminals will do to get what you have.
This story reminds me of my first car at 16. My dad bought me an old sheriffs car, it was still black in white, and I was really big on CB at the time so it had one or two antennas on it. I dont know how many times going down the road you would hear the truckers say that a unmarked unit just passed them.