Place the oil in a large skillet set over medium to medium-high heat. Add the onion and cook 2 minutes. Add the zucchini, bell pepper, garlic, chili powder, cumin and paprika and cook 3 minutes more, or until the vegetables are just tender. Add the corn and cook 1 to 2 minutes more, or until heated through. Season with salt and pepper, toss in the parsley, and serve.