Combine green tomatoes, onions, jalapeno peppers, serrano peppers, and red bell pepper in a large bowl.
Mix cilantro, sugar, garlic, oregano, and cayenne pepper together in a small bowl.
Fill a blender with about 2 cups tomato mixture, 1 teaspoon lime juice, and 1/4 of the spice mixture; blend to desired consistency and pour into a large bowl. Repeat blending with remaining tomato mixture, lime juice, and spice mixture, working in batches, until all ingredients are blended. Stir vinegar into salsa.
