For example, when you want to emphasize the contrast of a laid-back person living in a hectic city. I figure we can say something like "His laid-back personality is a [word] against/to the bustle of the city." but I have yet to find the right word for it
I also want the word to have a positive meaning, so it doesn't simply contrast with the rest but does so favorably.
Update: I thought of a word that is very close to this: A breath of fresh air. So it would help if the words you suggest also have a similar connotation.