C.R.S. § 42-12-204: Signal lamps and devices - street-rod vehicles and custom motor vehicles - definition.

(1) As used in this section, "blue dot tail light" means a red lamp installed in the rear of a motor vehicle containing a blue or purple insert that is not more than one inch in diameter.

(2) A street-rod vehicle or custom motor vehicle may use blue dot tail lights for stop lamps, rear turning indicator lamps, rear hazard lamps, and rear reflectors if the lamps comply with all requirements of part 2 of article 4 of this title.