Choose a neutral color such as white, cream or light gray, to balance out the bright color scheme. Use the trio of colors throughout the room to keep the entire space visually connected.
Furnish the rest of the room with white, black, wood tones or glass to let the red couch stand out against the celery walls. The other pieces should be muted or include hints of both colors, such as a celery and cream leaf-patterned armchair and ottoman next to the sofa.
Carry out the loud color scheme while adding texture and additional interest with textiles. Rugs that include red, celery and black geometric patterns will complement the entire room and ground the pieces and color scheme. Curtains, throw pillows, throws and rugs are easy ways to add color, pattern, texture and interest.
Hang black-and-white prints or modern artwork with a few loud colors, including red and celery. If you want the sofa and paint to stand alone, simply hang frameless mirrors or metallic wall sculptures, such as wrought-iron candelabras or copper pieces.
Accessorize the room with plants, candles, vases or lamps that play off the walls or the sofa. Mix it up with celery-colored candles and red glass pebbles inside clear vases, or an arrangement or bright red flowers in a celery-colored vase.