Regulatory signs are an essential part of traffic control and are used to convey specific instructions or regulations to drivers. The color and design of these signs play a crucial role in ensuring their visibility and understanding. While most regulatory signs have a white background, there are exceptions.

The red background on regulatory signs serves to grab attention and indicate a higher level of importance or urgency. Stop signs, for example, have a red background to immediately catch the driver's attention and convey the mandatory requirement to come to a complete stop. Yield signs also have a red background to indicate that drivers must yield the right-of-way to other vehicles.

Regulatory signs with a red background always feature a white legend, which is the text or symbol on the sign. This color combination enhances visibility and ensures that the message stands out clearly against the background.

On the other hand, regulatory signs with a white background may have a red or black legend, or a combination of both. The choice of legend color depends on factors such as readability and contrast. Red or black legends on white backgrounds are commonly used to convey prohibitions, such as no parking or no entry. The combination of red and black enhances visibility and ensures that the message is easily understood.

Overall, the color and design of regulatory signs are carefully chosen to ensure maximum visibility, comprehension, and adherence to traffic regulations. The consistent use of specific colors and combinations helps drivers quickly recognize and respond to the instructions conveyed by these signs, promoting safety on the roads.