What color is used for cultural features on older military maps?

The correct answer is red-brown, which is used for cultural features on older military maps. This color is specifically designated in the military mapping conventions to represent built-up areas and features that are man-made or constructed. Such features include things like roads, buildings, railroads, and other infrastructure that are vital for understanding the terrain in military operations.

In contrast, black is typically used for man-made features on more modern military maps, while brown is primarily reserved for elevation and contour lines indicating landforms. Blue is used to symbolize water features. Understanding the color codes on military maps is crucial for effective navigation and operational planning, as it allows soldiers to quickly identify and interpret various terrain elements and cultural landmarks.