Most contour lines on a map, which represent relief features and elevations, are denoted by the color brown. Green on topographic maps denotes vegetation such as woodlands, whereas blue denotes water features such as lakes, marshes, rivers, and drainage. The colors brown, green, and blue are used by convention rather than any specific meaning beyond their appearance to denote land and water.
A special case is yellow-orange sand dunes, which are common in parts of the United States and Canada. These areas are often called "yellow brick roads" because they appear on old US road maps that were printed before there was any real understanding of how deserts formed.
Other colors may be used for particular types of features. For example, pink represents volcanic activity. Purple shows signs of mining or other human intervention such as buildings or tunnels. White indicates ice fields or other frozen surfaces while black shows actual roadways or railroads.
The colors of the spectrum can also be used to show characteristics of the earth's surface. For example, red marks areas where there has been much loss of life due to war or natural disaster.
Blue marks areas where there has been much loss of life due to pollution or environmental damage.
Green marks areas where there has been much loss of life due to poverty.
The color blue is used on topographical maps to depict water features such as perennial rivers, canals, wells, tanks, and springs. On a map, the color brown denotes most contour lines, which represent relief elevations and features. The color red shows places where there are active faults or volcanic vents.
Water is blue; land is brown; cities are black; roads are gray; tracks are white; mountains are green; forests are dark green; fields are yellow; desert is white; ice is black; and other features are colored according to their use. The quality of representation of different types of features varies depending on the scale of the map and the amount of detail shown.
For example, on large-scale maps that show terrain features but not all details, the colors are generally accurate but may not be precise enough to identify certain objects. GIS software allows you to change the color of any feature on the map. You can also add labels to some features on the map to identify them more easily. For example, if you were mapping a park and wanted to label each tree, you could do so with this information.
Color is important when interpreting maps. For example, the presence of water in an area will usually be indicated by the color blue, while areas without water may appear brown or grey.
Contours are often depicted in brown, bodies of water in blue, borders in black, and grids and highways in red on topographical maps. Different colors can be used to depict area characteristics on topographic maps. Color is most typically used to illustrate differences in height on physical maps. For example, green indicates low land while red indicates high ground as seen from space.
Color can also be used to indicate different categories of features. For example, oil fields are usually colored light yellow or orange. This makes them easier to see on topographic maps.
On political maps, color is used to highlight different countries. For example, red for Russia, blue for Canada, and white for the United States.
On economic maps, colors are used to show different sectors of the economy. For example, gray represents mining, blue technology, and orange agriculture.
Maps have been created using many types of media including paper, film, and now computers. The medium that is chosen should match the subject matter of the map. For example, if the map were being created for navigation, then it would make sense to use lines rather than colors to show routes and directions.
When creating a computer map, there are several options when it comes to colors.
Color Schemes on a Military Map
|Brown||Identifies all relief features and elevation, such as contours on older edition maps, and cultivated land on red-light readable maps.|
|Green||Identifies vegetation with military significance, such as woods, orchards, and vineyards.|
Green will be used on most topographic maps to represent vegetation, national parks, and animal control zones. They'll also use blue to represent rivers, lakes, and other bodies of water. Green shows up as many different colors on modern maps, but they usually are dark, dull greens.
On old maps, green showed up as a light color called verditer. This color comes from the mineral phospate when it is stained by chlorophyll found in plants.
Blue shows up on most maps with waters, while red shows up on desert maps to represent fire or heat sources. The American Land Surveyors' Association's standard map colors are mostly based on these two values: red for high intensity and blue for low intensity.
Map colors don't always follow this rule. Some maps may have more than three colors, while others may use all four values (red, orange, yellow, and green).
Maps can also have gray or white areas where there is no data available. These are usually open spaces within cities or areas that were once covered by trees but now aren't due to urban development. Also, some military maps may have blacked out areas related to national security.