Here in New Jersey, we carry yellow foam emergency blankets for multiple uses on the ambulances, as well as tarps. Theirs no uniform color on what you use . Just as long as it prevents onlookers from seeing the body. If we arrive on scene with a fatality, in which resucitation won't be effective i.e. (massive fatal injuries, obvious signs of death, prolonged cardiac arrest, etc), then we may cover the body or vehicle with a tarp or a blanket. The only person that can move the body is the medical examiner, and they will place the deceased in a body bag, usually black or white.