Wash all vegetables thoroughly, chop bell peppers, slice zucchini, cut red onion, and rinse mushrooms.
In a large mixing bowl, combine teriyaki sauce, grated ginger, olive oil, garlic powder, black pepper, and salt. Mix well.
Add prepared vegetables to the marinade and toss gently to coat. Let marinate for at least 15 minutes.
Assemble skewers by threading vegetables onto them, alternating types for variety.
Preheat grill to medium-high heat. Grill skewers for 10-12 minutes, turning occasionally until tender and charred.