Is there any correlation between colours of countries on a standardised world map?

Question

Is this a historical/political/cultural thing or simply done for the sake of coherence?

Answer 1

On a standard map it's for "coherence" or asthetic appeal. However there are maps that use color coding to represent things, usually population.

Answer 2

Back when the "Sun never set on the British Empire" every country in the Empire was pink on a world map. Otheriwise I doubt there has ever been a reason for what colours are on the map.