Brown
Brown is a very earthing colour, though it can induce inertia and boredom if overused. Paler tones like beige are neutral and quite restful, much easier to live with.
Brown evokes the colour of soil and wood... in fact using polished wood as a method of introducing it into the environment is more effective that using wall-papers or paints usually because you get so many different tonal qualities.
Wearing brown in any large amounts tends to give the viewer the impression of 'dullness'.