In nature's color code for food, red means a lot of things, none of them subtle. In a cluster of ripe bing cherries, it's a lascivious wink. On bell peppers, it telegraphs "Pick me! Now!" In a blood-drunk hunk of fresh meat, the color calls to our passionate, violent appetites. Then there's Marita and William Brown's red velvet cake. Only the proud, the brave, and the tradition-bound can add that much food coloring to cake batter. Whether your nature calls out for red velvet cake with nuts or without, when you bring a bite of that moist, wine-colored cake slathered in cream-cheese frosting to your lips, sniffing out the hint of cocoa, you'll give Mother Nature her due for blessing the husband-wife pair with such baking talent. In fact, all the traditional Southern cakes and pies at Marita's Sweet Potato Pie Co. are worth taking home. It's just that the red ones call out the loudest.