You could use any shade of Taupe. Or use soft Cream/Antique White, to keep it neutral...& stick to a Black & White theme....using colors as your accents. This choice would make it easy for you to change color in the room...giving you Carte Blanche', at any time. If you prefer to go darker on your walls...you could choose a deeper tone of Gray, Gold, Mossy/Sage Green...Or even a subdued Purple is awesome. People who like the paler tones of paint could go with soft aqua blue, peach, slate blue or a very pale yellow on the walls. These would bring in a cooler tone to the room. Gray is Neutral. Most any color goes with it. A lot of your choice depends on what style your furniture is. If it's traditional..try the Mossy Greens, Grayish Purple, Gold or Sage Green. If it's Modern...you can go with Black & White tones or Taupe...Then you can use accents with brighter/deeper colors, such as: Reds/Burgundy, deep Golds, Purples, etc. But if you prefer a paler pallete...try Aqua, slate blue, Peach, or a pale yellow. Happy decorating !!
It depends on your trim. If you have white trim then you could use a mixture of color as stated above. Go to the paint store. Ask for complimenting colors of gray. Take a pillow or couch cushion with you as the paint sample chips look different under store lighting then they do at home. If you are a "color loving person" you could try black, white, taupe if not or do a focal wall of maybe 2 shades darker than your furniture in gray and the rest in off-white or white. You could do all cream and accent the room with variety of blues, greys and pick a opposite color like red or orange for a pop color in the room.
I like shades of coral with gray. Something in the tomato red color is a good also. When the gray is pale I like teal.
You should use light gray color shade or something like coffee color shade. I think that color look good.