POUR combined dressing and seasonings over fish in shallow dish; stir to evenly coat. Refrigerate 15 min. to marinate.
HEAT grill to medium-high heat. Remove fish from marinade; discard marinade. Thread fish, onions and peppers alternately onto 4 skewers.
GRILL 8 to 10 min. or until fish flakes easily with fork and vegetables are crisp-tender, turning occasionally.