The orange numbers on the roof are cruisers before 2000. That year they went to a reflective white number for the roof. They assist the airwing with radio commo' with cruisers on the ground. If you see a 1999 cruiser or older with white numbers they are faded and haven't been replaced. All the numbers on the roof match those on the front fenders which match those on the front and back plates. Color has no special designation other than the Trooper probably just replaced them.