The Monroe Fire Marshal is offering some insight into flashing colored lights drivers may see on other passenger vehicles. A flashing green light indicates EMS personnel responding to a 911 call in their personal vehicle, meeting the ambulance or responding to their building. A blue light indicates a volunteer firefighter responding to their firehouses to provide the manpower for emergency apparatus to respond to a 911 call. But Monroe's Fire Marshal says sometimes the volunteers are responding directly to the scene as a first responder. Motorists are asked to treat these flashing lights like any other emergency vehicle and yield the right of way as a courtesy.