What color on a map indicates hydrography?

The color blue on a map is universally used to indicate hydrography, which includes water bodies such as rivers, lakes, and oceans. This standardization allows for quick identification of water features, which is crucial for navigation, land use planning, and environmental assessment. Understanding this color coding is essential for anyone engaging with maps, particularly in military operations, where recognizing terrain features, including water sources, can impact strategic decisions.

In contrast, other colors serve different purposes: red often denotes man-made features or boundaries, green indicates vegetation or forested areas, and black typically represents built-up areas or roads. These color conventions help users interpret maps effectively and locate features relevant to their objectives.