Place fish in Sunset Marinade for at least 15 minutes, but no more than 1 hour. Cover and refrigerate while marinating.
Preheat grill.
Assemble skewers, starting with fish, onion, bell pepper, then shrimp, onion, bell pepper, followed by scallop, onion, and bell pepper. Repeat until skewer is full, leaving 1 inch at each end of the skewer. Grill for about 12 minutes or until fish is just cooked through, turning skewers every 3 minutes.
Sunset Marinade:
2 tablespoons pineapple juice
2 tablespoons orange juice
1/4 cup low-sodium soy sauce
2 tablespoons chili sauce
2 tablespoons fresh ginger, peeled and crushed
Combine all ingredients in a shallow nonreactive bowl or dish.