When you go to buy a tile in Civilization 5, some tiles have a pink border. Why is this?
Answer
Unlike previous versions of Civilization, in Civ V, territory around a city expands one tile at a time. The pink highlighted tiles are the ones that are next in line for expansion through culture. Consequently, they are also usually the cheapest tiles to purchase.
Attribution
Source : Link , Question Author : Bryan Roth , Answer Author : sjohnston