In the United States, comfort reigns tyrannically over leisure clothing, and some men worry about looking sufficiently relaxed wearing a jacket when off duty. Social concerns aside, a man is simply more attractive in a sport coat than in a sweatshirt, and this fact should encourage those who fear drawing accusations of looking "uptight" if they wear anything they can't play basketball in. The sheer beauty of tailored clothing transcends this country's present obsession with being laid back.
Like its darker cousins medium and charcoal gray, a light gray bespoke suit has no opposites on the color wheel. It is simply a shade of black.
That doesn't mean that nothing will clash -- any color in a
shade of similar lightness will look like a mismatch with light gray.
No, what there needs to be is a clear distinction between how close the
gray is to white and how close the colors worn with it are to the same
Deep colors help make the contrast clear, as do patterns.
Plain white shirts will usually be too close to light gray to be a
good match, and should be broken up with a pattern of some kind, ideally
in a dark color.
A patterned gray suit is an ambitious sartorial challenge.
Pinstripes in a dark color can be an interesting inversion of
traditional business-wear (dark gray with light-colored pinstripes), but
dress shirts then need to avoid clashing with both the light gray and
the color of the stripe. Plaid in such a light color looks odd, and big
windowpane checks on a light color is aggressively retro -- one of
those looks better left in the 1970s. Texture in the fabric can make a
less jarring alternative to a pattern in a dark color and help emphasize
that the custom made suit is light gray rather than off-white.