Peel potatoes and onions, cut into eighths. Wash peppers and cut into cubes.
In a small bowl, combine 3 tablespoons oil, salt, pepper, and 2 teaspoons paprika powder. Brush mixture onto chicken legs, toss remaining mixture with vegetables. Cover and refrigerate chicken until ready to bake.
Put vegetables in a baking dish, place chicken legs on top. Roast for 40 minutes, adding water if vegetables look dry. Chicken is done when the thickest part reaches 74°C (165°F).