NRS 486.261: Tail lamps.

1. Except as otherwise provided in subsection 3, every motorcycle or moped must be equipped with at least one tail lamp mounted on the rear, which, when lighted as required by NRS 486.011 to 486.381, inclusive, emits a red light plainly visible from a distance of 500 feet to the rear.

2. The tail lamp must be wired to be lighted whenever the head lamp is lighted.

3. The tail lamp on a motorcycle may contain a blue insert that does not exceed 1 inch in diameter.