[wadey]

* According to Regulation 11 of the Road Vehicles Lighting Regulations only red light may be shown from the rear of a vehicle. There are a very few exceptions to this, including amber from indicators.
* Red light must never be shown at the front of a vehicle
* Blue should be avoided, since it is strongly associated with emergency vehicles.
* The law covers lamps at the front and sides, and not light coming from the underside of vehicles. Neon systems aren't lamps, but they do create light that's easily seen. The wisest course is to abide by the colour regulations outlined: red at the rear, amber at the side, and white in front.