Sauté green pepper, onion, pickle relish, red pepper, and parsley in 1/2 cup butter in a large skillet until tender. Stir in 1 cup breadcrumbs, Worcestershire sauce, salt, pepper, egg, and oysters. Spoon evenly into 12 seashells or ramekins. Cover; chill at least 1 hour.
Sauté 1 cup breadcrumbs in remaining butter until lightly browned. Top oyster mixture with sautéed breadcrumbs; sprinkle with paprika. Place shells on baking sheets. Bake at 350° for 30 to 35 minutes. Serve hot.