you could do a Coruscant kind of idea...kind of like Padme's living room, with blue-ish walls and silver accents. Very cosmopolitan. Or you could do Empire Corusant(or, excuse me, Imperial Center), with lots of grays. Or, in the X-Wing series, Ysanne Isard had a room that had very few furnishings and blue carpet with red trim. Or was it red carpet with blue trim? I don't remember. Well, just some thoughts.