By painting the walls a nice soft gray/taupe (try Hc-172), there is only a soft contrast with the painted millwork/brick wall that is a warm white (try OC-117). This tone on tone effect visually creates a larger space, and softens the look more than just using one tone of off white.
There is a focal wall painted in a gray/blue tone (try 2123-30) this adds a punch of colour…but can also be painted out over time if needed.
As for the sofa colour, you are completely open-taupe, charcoal, chocolate, black, purple…you name it!
Are you re-designing your basement? If so, come visit us at the store with pictures/samples of your space and our staff will be happy to guide you in the right direction.