Men's Slim Fitted Suit In A Plaid Pattern With Solid Contrast Vest.   Plaid suits are considered fashion-forward because of their clean, modern, and colorful appearance.  Plaid suits can be worn for any occasion or event, but they are more formal, so they should only be worn when appropriate. For example, a brown plaid wedding suit can be dressed up or down to fit a range of wedding styles.  When choosing a suit, you can also consider details like pockets, buttons, vents, pant styles, and lapels.