While older maps and globes were often painted in one color, more recent ones often feature multiple colors. These colors help observers to tell the difference between specific areas on the map or globe. For instance, blue is often used for waterways. Green or brown is most often used to represent land. If you are looking at a map of the United States, the different states are often shown in different colors, helping you to more easily see where one state ends and another begins.
On a physical map, various elevations and land features are shown. To more easily separate one area from another, colors are used to represent each type of land. For instance, mountains may be show in brown to reflect their higher elevation. Areas of land that are lower and flatter may appear in green. Waterways can be shown in various shades of blue to represent different depths of the water. These maps often have a key that helps you understand what each color represents.
Some maps are meant to show you where to find a specific location. A map of a city, for example, will show various streets and points of interest. Different colors may be used for different types of roads to help you know which streets are residential streets and which ones are highways. Smaller side streets may be shown in yellow with highways highlighted in red. Various types of landmarks and points of interest may appear in a specific color or even a specific symbol. Forest land or parks, for instance, are often shown as green areas.
Some maps related to geography are used to show you specific information about certain areas, such as the climate, populations and other relevant data. The primary goal of these maps is to more easily correlate information to specific areas on the map. These maps often use colors to show ranges of information. For instance, on a map that shows you the average rainfall, red may show areas with the most rainfall, orange may show moderate rainfall and yellow may show little or no rainfall. Various shades in between may also be used to show more ranges if necessary.