Question

on a map the use of the colour blue shows​

Answer 1

Answer:

for water

Explanation:

Political Maps

Blue often represents water and black and/or red is frequently used for cities, roads, and railways. Black also shows boundaries, with differing types of dashes and/or dots used to represent the type of boundary: international, state, county, or other political subdivision.

Answer 2

Answer:

No colour is selected that this will be used only for particular thing....but in general blue is used for water