they use compass' and map.Also before maps were invented they used the sun,moon,stars, and color of ocean (if at sea)
Google Maps, Yahoo! Maps and British Ordinance Survey maps use a mid-blue colour for all water features (rivers, streams, lakes and the sea).
blue is the color
Geologic maps use color to represent various types of geologic features or units (a particular type of rock with a known age range).
The color blue.
maps.Google.com and search for china. I collect cloth maps (aka "silk maps" or "escape maps") from WW2 and Cold War (1950's). Colth maps were issued to aircrews for use in case they were shot down behind enemy lines or in foreign territoroy. During the last year of WW2, the US produced thousands of cloth maps in full color for use when the Allies invaded Japan. The war ended so many of these maps were never issued. And you can still buy these that include portions of China. These maps have color topography detail and details of towns, roads and rivers. It is very beautiful maps. Also good reference map.
Maps do not have to be in color but color helps make interpretation easier.
It varies on different maps.
There is a website called Maps of the World and it has maps of the world, of countries, and of states, all of varying types, including maps that color code based on political system.
Geographers use maps because that's what geographers do for a living. Geographers use maps to learn about the Earth's surface. That is their job.
usually brown, but sometimes an ice grey color
The blue on maps represents lakes,oceans, seas,aka water