Quote from the NYS Driver's manual, chapter 5:
"Personal vehicles driven by volunteer fire fighters responding to alarms are allowed to display blue lights, and those driven by volunteer ambulance or rescue squad members may display green lights. Amber lights on hazard vehicles such as snow plows and tow trucks warn other drivers of possible dangers. Flashing amber lights are also used on rural mail delivery vehicles and school buses to warn approaching traffic of their presence. The vehicles displaying blue, green, or amber lights are not authorized emergency vehicles. Their drivers must obey all traffic laws. While you are not required to yield the right-of-way, you should yield as a courtesy if you can do so safely."
http://www.nydmv.state.ny.us/dmanual...al.htm#col-lgh