GPS Colours is a mod that changes the colours of the GPS and world map. Discovered roads are white, discovered lots are purple. Undiscovered roads are beige and undiscovered lots are default grey. The route marker is now green and the arrows on it are black. However it seems discovered city names are the same as the roads, so the white of it might be similar to undiscovered ones, but luckily we have orange orbs on the map for that. You may or may not need all the map DLC