Your brown couch is likely the largest piece of furniture in the room, meaning that it commands visual attention. If you want to ensure that you strike just the right balance of color in the room, employ the 60-30-10 rule that professional decorators use. This rule says that to achieve balance, 60 percent of the color in the room should come from the the paint on the walls, 30 percent should be derived from furnishings like the couch, chairs, drapes and area rug and the final 10 percent should be introduced through accents like flower arrangements, artwork, scatter pillows and throws.
Brown is a color found in abundance in nature. Couple it with another nature-inspired shade for an earthy, natural looking decor. Try any shade of green, burnt orange like you might see in a sunset or the lavender and yellow shades of freshly bloomed flowers. Minds are accustomed to seeing the colors of nature within the same palette, making them an ideal choice for interior decor.
If that brown sofa is a tad too sedate for you, give it a modern pop by adding bold accents. Lipstick red pillows, artwork and lampshades can be the start of an art deco room. Cream colored accessories will work if you're aiming for minimalism. Blues can lead to a country-style decor. You can use both orange and black in a contemporary space.
You can achieve the monochromatic look by layering different shades of the same color into a room. Monochromatic works well in a clean, sophisticated decor. For example, if your sofa is dark brown, layer it with a few light brown scatter pillows and a light brown throw. Anchor the space with a medium brown area rug that matches the window treatments. Paint the walls a light tan and the ceiling an even lighter shade of the same tan.