red with white for stop signs, yield, and forbidden actions (such as No Parking)
green with white letters for informational signs, such as directions, distances, and places
brown with white for signs to parks, historic sites, ski areas, forests, and campgrounds
blue with white for rest areas, food, gasoline or petrol, hospitals, lodging, and other services
black with white for commercial, exempt, special, and signs were used in the past
white with black (or red letters) for regulatory signs, such as speed limits (or parking)
yellow with black letters and symbols for warning signs, such as curves and school zones
orange with black letters for temporary traffic control zones and detours associated with road construction