Minor refactoring in Color

Mostly motivated by line length and a plain `except:`.
Player-colored versions of old cityinfo settlement icon

These are not simply recolored but also manually adjusted.
Use player-colored settlement icon in cityinfo

Replaces the old (temporary) player flag that was pretty ugly in the new
configuration.
Also use colored settlement icon in account tab

This is still a hidden button accessing the settlement production
overview, but why not just update to a more advanced placeholder.