study the color wheel;& the rainbow. Study aura colors & what they mean. A popular book is by Pamala Oslie(see facebook page). Study "complimentary" colors and colors that look good on some people & not others. Turquoise looks good on everyone. Blue goes w/just about every color. Blue is the favorite color in the U.S.
It depends on the shade of blue, because it could be a light sky blue or dark navy blue. But, I think any shade of gray would match with blue. And black, white, or any other mixtures of dull colors that would make blue stand out.