What should a vehicle's rear indicators display?

The rear indicators of a vehicle are essential for signaling to other road users when a driver intends to make a turn or change lanes. They must display red or orange lights to comply with safety regulations and ensure visibility. This requirement is in place because red and orange colors are universally recognized as indicators of movement or change, helping to reduce confusion among drivers and enhance overall road safety.

Using red lights specifically for indicators is common in many locations, whereas orange lights are often used to denote turn signals. This color distinction helps in clearly indicating the type of maneuver a driver intends to make, thus minimizing the risk of accidents. The other options suggest alternatives that do not align with the standards for rear indicators, as they either do not provide the necessary signaling function or use colors that are not recognized for this purpose.