Summarize this article:

If your regular coat isn't warm enough, opt for a parka when styling your business or evening wear. Choose a neutral parka rather than a multi-colored or patterned jacket.  To look stylish, pick a parka 2–5 in (5.1–12.7 cm) longer than your jacket. Select a black or grey parka with a dark-colored suit, for example. Go with a brown parka with a tan or khaki combination. If you want to go out on the town but need to keep warm, throw a parka over top. Parkas make great coat options even with formal outfits. Don't forget your tights!  Choose a brightly colored parka or one with a subtle pattern if wearing a solid dress. Choose a neutral or plain parka if wearing a patterned or bright colored dress. If you want to elevate your parka for a dressier look, pick a suitable footwear option. Either way, you'll keep warm and look great!  Choose a full brogue or Oxford for an attractive, unisex option. If you want a little height, choose an ankle boot.

Summary:
Wear your parka over a suit for a business-appropriate option. Put on a parka over your favorite dress for an evening look. Pair your parka with brogues, Oxfords, or ankle boots for an easy nighttime style.