All RS-2s were originally painted black with yellow lining/lettering. Yellow zebra stripes were applied later. The original 244 engines were equipped with air coolers. Later in life, most were reconfigured with water coolers. (The configuration can be determined by the orientation of the exhaust stack on the long hood. If the stack is off set to one side, the unit has an air-cooled turbocharger. If the stack is centered on the long hood, the unit has a water-cooled turbocharger.)