What color represents signage for road user services such as hotels and gas stations?

Blue is the color used to indicate signage for road user services, which include amenities such as hotels, rest areas, and gas stations. This color is designated specifically for informational signs that assist drivers in locating essential services along the road. Blue signs are easy to recognize, allowing travelers to quickly identify necessary services during their journey.

Other colors serve different purposes; for example, green typically provides directional guidance, indicating distances and directions to various locations without the emphasis on services. Red is generally used for stop signs, yield signs, and emergency vehicles, indicating caution or prohibitive actions. Yellow is associated with warning signs about potential hazards on the road. Therefore, blue is distinctly associated with road user services, making it the correct answer.