DO NOT ENTER signs use which combination of circle color and background color?

• A. Blue circle on a white background
• B. White circle on a red background
• C. Red circle on a white background
• D. Red circle on a black background

Answer: (C)

Do Not Enter signs rely on a red circle to signal prohibition, with a light background to maximize contrast. The red circle instantly communicates that entry is not allowed, and the white background around and inside the circle makes the symbol stand out clearly against road surfaces and in different lighting. This combination—red circle on a white background—is chosen for quick, universal recognition, so drivers can respond immediately. Other color schemes either imply different instructions (blue circles indicate mandatory actions) or reduce visibility, which is why the red circle on a white background is the standard for Do Not Enter.