I have brown furniture, what color should I paint the walls and what color carpet should I get?

I want to get new color carpet, my boyfriend wants to get a dark Grey carpet, paint the walls a real light Grey and the curtains and trim brown, so everything matches... i dunno any advice??????I have brown furniture, what color should I paint the walls and what color carpet should I get?
that sounds great but dont get really dark carpets. you could also paint the walls a tan and do the carpets beige for a warmer feel