What color reflector is required on the rear of a bicycle?

A bicycle is required to have a red reflector on the rear for safety and visibility purposes. This regulation is in place to ensure that cyclists can be easily seen by other road users, especially during low-light conditions such as at dusk or nighttime. The red color is universally recognized as a warning or stop signal, making it an ideal choice for enhancing the visibility of bicycles from behind.

Using a red reflector helps alert motorists and others to the presence of the bicycle, reducing the risk of accidents. The other colors, such as white, blue, and green, do not fulfill the specific requirement for rear visibility on bicycles, as they are used for different signaling purposes or reflect different types of objects. Therefore, the correct use of red reflects the safety standards established for bicycles on public roads.