I feel in love with the green and brown combo a couple of years ago when we designed my daughters wedding. If you think of it as celery and chocolate, it would make for a pretty unappetizing snack, but it's a scrumptious color pairing. Using these colors sparingly with lighter colors like white, cream and beige results in a soothing, comfortable and elegant look. Take note of the ratios between the light colors and the celery and chocolate accent colors in each of these rooms; it's a big part of what makes them so successful.
Case in point (above): The green walls provide the biggest swatch of color in the room, picking up on the green pillows and window treatments. The dark coco colored furniture provides the right dose to ground the room.
The green in the above room brings the outdoors in along with the beautiful lush palm sitting next to this bamboo seating area.
The color palette continues throughout this home, resulting in a sophisticated and inviting living room. The chocolate and cream zebra-print ottomans are enhanced by a few celery accents. The reset of the light room is bathed in natural light.