Which colors are used in traffic signals?

Answer: B — Red, yellow, and green

Traffic signals utilize a standardized color system to convey specific instructions to drivers. The correct colors used in traffic signals are red, yellow, and green. Red indicates that vehicles must stop, signaling drivers to halt before the intersection or crosswalk. Yellow serves as a warning that the light is about to change, cautioning drivers to prepare to stop if it's safe to do so. Green signals that it is safe for vehicles to proceed through the intersection. These color conventions are designed not only for uniformity across various jurisdictions but also for instant recognition by drivers, thereby enhancing safety and traffic flow. Other color combinations are used for different purposes in traffic management and signs but do not serve as the primary colors for traffic signals.