Six colours are used in a survey map to show various features. They are as follows: Black: All names, river banks, broken grounds, dry streams, surveyed trees, heights and their numbering, railway tracks, telephone and telegraph lines. Yellow: All cultivated areas. Green: All wooded/forested areas, scattered trees and scrubs. Brown: Contour lines, their numbering, stony waste, sand features. Blue: All water bodies, where they contain water. Red : Grid lines and their numbering, roads, cart tracks, settlements, huts and other buildings. Note: Sometimes we find white patches here and there to show barren lands.