Without seeing it nor the colour on your walls (which also plays a part), I would say you could take any one of the colours from your carpet as your colour for the upholstery. Yes you can choose two complementary colours for your upholstery but make sure they work tonally. (To do this take a picture of the colours and render them black and white; the colours for your upholstery - even if they are different - should have the same level of grey in the b&w photo).

Sounds okay if that fits with the style of the house.

Please provide pics of the space or any furniture or other things to consider. You haven't really given much information that would allow anyone to help you.

Ok. Sorry for asking the question in such a way. Ill try to explain here. What I am thinking right now is that each room will have a single wall with a color and rest three in a shade of white matching with the single colored wall. The colors that I have currently in mind is grey for living room (Wall behind TV), LIght Blue in MBR and Brown for kitchen and other room. These colors would be for a single wall in their respective rooms. I need help in deciding which shade of white to go with to paint the other three walls in each room.