Rough idling could be a dirty idle control valve (icv, likely), a failing crankshaft position sensor (cps, unlikely) or a bad/dirty throttle position sensor (tps, also unlikely).
The cps's resistance should be tested when the engine is cold and when it is hot, to see if it is in range according to its specs. This requires a digital multimeter, which is cheap. The tps's switch can be unplugged and both the tps and the switch can be cleaned out and affixed back. The ICV might be a problem for you to remove due if it is located in an inaccessible place. Unfortunately that's the best bet for your idling issue.
The idling situation should have nothing to do with your blue smoke issues. The idle probably got worse because your icv got dirtier and not because the weather changed. Probably.
Last edited by robertobaggio20; 11-11-2012 at 09:45 PM.