A Settlement with an orange and blue Border. Borders can be seen form the overworld map.
The Borders of an Empire shows the Empire's territory. They incorporate hex tiles that belong to a specific Empire. Most hex tiles provide Resources, which can be harvested if the tiles lie within the borders of a Settlement.
In general, each Settlement owns the tile it is on and the six tiles adjacent to it. Borders do not expand past these six tiles. Settlements can share a Resource tile (including Settlements from different Empires) and will receive the same Resource Yield from Harvests.
As a Cosmetic[]
A Border's color can be changed through Border Cosmetics that can be crafted in the Workshop.