On a map, what does the color blue primarily represent?

The color blue is commonly used on maps to represent water features, such as rivers, lakes, oceans, and other bodies of water. This convention helps map readers quickly identify where water is located in relation to other features on the map, facilitating navigation, geographic understanding, and reference. Water bodies are significant in various contexts, including environmental studies, urban planning, and recreational activities, making it essential to represent them clearly. While other colors on a map serve to denote different elements like vegetation or man-made structures, blue specifically denotes water, making it easily recognizable and universally understood in cartography.