Use a colorful garnish to contrast with the dark brown of the beans.
Soak beans overnight in cold water to cover. (Drain or not, as you prefer.) Melt butter in soup kettle, saute onions, garlic, celery, and carrots until soft. Add stock, bay leaf, curry powder, chili powder, and beans. Simmer, uncovered, 2 hours or until beans are tender. Add more water as necessary. Press through food mill and return to kettle. Season with salt and pepper, reheat, and garnish with sour cream and chopped parsley.