What color represents warning signs for upcoming hazards?

Warning signs that indicate upcoming hazards are crucial for ensuring driver safety, and they are universally marked with black letters or symbols on a yellow background. This color combination is designed to catch the driver's attention quickly and signal the need for caution. Yellow is often associated with alertness and caution, making it an effective choice for signs that warn of potential dangers ahead, such as curves, intersections, or construction zones.

The other color combinations do not serve the same purpose. For instance, signs with black letters or symbols on a white background typically convey regulatory information, while white letters or symbols on blue signals informational signs, such as those indicating services or amenities. White letters or symbols on a green background are used for indicating guide signs, such as directions to cities or points of interest. Each color scheme is intentionally used to communicate specific messages to drivers, with yellow serving the distinct function of alerting them to hazards.