Prep: 15 minutes; Cook: 6 minutes. If you can't find yellow zucchini at the grocery store, you can order it from a specialty-produce purveyor (like Frieda's, www.friedas.com) or use yellow squash.
Arrange zucchini on a baking sheet; drizzle with 2 tablespoons oil, turning zucchini several times to coat both sides with oil. Sprinkle on both sides with garlic, oregano, mint, salt, and red and black peppers.
Set up your grill for direct grilling, and preheat to high. If you'll be using a vegetable grate, preheat it as well.
Arrange zucchini on grill or grate, and cook 3-4 minutes per side or until browned. Transfer to a platter, and arrange in an attractive pattern. Drizzle 1 tablespoon oil over zucchini; garnish with lemon wedges. Serve hot or at room temperature.