What does the color blue represent on a military map?

On a military map, the color blue is universally used to represent water features. This includes not only large bodies of water such as rivers, lakes, and oceans, but also smaller water elements such as streams and ponds. This color coding allows for easy identification of water sources, which is crucial for navigation, planning movements, and understanding terrain. The standardized use of blue for water helps soldiers and planners quickly assess the geographical features of the area they are operating in, ensuring effective decision-making in the field.