Irritatingly I didn't take a screenshot before alt-tabbing to see if this had already been reported or not, and upon alt-tabbing back in to take one the city HUD is now not showing up at all, which I guess is another bug all of its own. Is there a keyboard shortcut to switch it back on?

Essentially I'd met another faction and discovered one of it's cities. When I went back to my two cities thet had both taking the same name and colour of the opposing faction.

If it happens again I'll be sure to snap a screenie.