Make sure that you get test boards (we do it by getting a large sheet of drywall and cutting it into 4-5 pieces. Get samples of any colors that you are considering. Paint one color on each piece. Move them around during different times of the day to see how they react with your light and the surroundings. Much cheaper than making a big mistake. Small paint chips aren't large enough to really make a decision.

Giving color advice online is really dangerous as no one else sees your space as it truly is except you. Monitors are all different even if pictures are provided. Having said that, we have used SW7051 Analytical Gray before (has a bit of a green tint). SW 7043, SW7044 and SW7641 all appear to be nice mid-range grays.

Multiple layers of gray look nice. Shown: Versatile Gray and Spalding Gray both from Sherwin Williams