Cars with accessory lights and strobes could land motorists with a fine or a court appearance, police have warned.

In recent years there has been a growing trend for lighting accessories such as tinted headlights, undercar strobes, illuminated washer jets and grill lights. But police are warning that not all of these devices are legal.

With the exception of reverse lights and indicators, lights on the front of a car must be white, and on the rear they must be red. They must also have a steady beam.

Hertfordshire Chief Inspector Paul Brooks said: "We are not trying to spoil anyone's fun, but our main purpose is to ensure road safety.

"As an experienced road policing officer I am aware of the the unpredictable reaction of drivers to the sight of a blue lamp. An inexperienced driver in the same position would not be aware of this and a collision could occur."