This feature improves the overview of the fields in the map. Without any settings, certain villages will be automatically marked - your own villages, villages of your alliance and federation and villages that your alliance is in war with are. Each of these gets a different colour.

• Yellow: Villages marked with yellow frame are your villages
• Blue: Villages with blue frame are villages of your ally members 
• Light green: Confederate village are marked with light green colour
• Red: Villages, which are currently enemies of your alliance are marked red

Note: There's no colour for oases. Furthermore these colours might change if you or your ally define own colours for specific players or allies.