Seeing the nice new shiny improved mills with their pretty blue roofs made me think that it'd be cool if the level 6 Mayor's house changed from green roofs at level 5 to blue at level 6. The level 6 Mayor's house hardly looks much different from the level 5, and it would be a trivial change, I assume, in coding terms.
Adds nothing to game function, of course, but it'd look cool!
