As I live in the Chicago area, a good winter coat is a necessary wardrobe stable. Otherwise, nobody would leave the house from November to March (or sometimes from September to May!), which puts quite the damper on life in general.
Most of the time, when I see winter coats, they're an array of black, brown, gray, navy, and tan. Neutrals are nice, but they get a bit... blah.
Why not a bright, bold color? It helps you stand out in the crowds, and they're much more cheery to put on than something on the drab side. Right now, my winter coat is a vivid blueberry, almost the same shade as the sky. It makes me smile when I catch a glimpse of myself in it, just because it's such a cheery color.
Of course, when I say a "bright winter coat," I don't mean a big puffy ski parka. Unless you are actually skiing, or live in a climate where serious outerwear is seriously necessary, a classic silhouette in wool, leather, (faux) fur, or even certain synthetics is always much more polished-looking than something you'd see in the Winter Olympics.
Choose a color you love, in a material that works well, and you'll always look and feel amazing.