Gray is a soft and subtle color to paint with, and as far as matching it with other colors, it is basically neutral. Like white, gray can be matched with almost any color suitably, but the tone of the gray should be considered. Some gray paints are more metallic in nature--boarding on silver--which may not match well with earthy browns or oranges. For a subtle gray, if it otherwise fits the decor or design, it can match with most other color choices.

On the Other: Gray Needs Contrast

When painting with gray, avoid having the entire space seem too neutral or drab. Too much gray can create a downcast and cold feel. Soft yellows and reds compliment gray while at the same time adding contrast, and striking shades of blue or purple can give a gray room just the right amount of shine and brightness.

Bottom Line

Gray is a fairly easy paint to match, because like white or pewter, it is neutral. Gray can be used to compliment more pronounced colors or they can be used to compliment a dominate gray choice. Too much gray risks creating a drab color scheme, and even with modern decors and designs, a splash of yellow, red or blue can work wonders.

Source:

Zimbo.com: Gray Paint Colors