The other type of tailoring workhorse. The cavalry. Just when your navy suit was about to give up the ghost (or just head to the dry cleaners), grey rides to the rescue, ready to make you look good. As a general rule, charcoal skews formal and wintry, while light grey is more casual and summery. A mid-grey will give you the most scope for day-in, day-out, year-round wear. Ideally, you want to choose a shade â€“ and fabric â€“ with mileage, such that you can wear the trousers with your navy jacket and vice versa.