In a bowl, combine the chili powder, oregano, and cumin. Set that aside for now.
In a skillet, heat your oil over medium heat. Sauté the bell peppers, onion, and garlic until tender, with just a little bit of golden edges. Stir in the spices.
In your slow-cooker, combine all of the ingredients except the rice. Stir it all together.
Cook this in your for 4-5 hours on high, 8-10 hours on low, or until the beans are tender.