Whisk apricot preserves, soy sauce, scallions, olive oil, garlic and chili powder together in bowl, add beef, toss to coat. Marinate for at least 1 hour in refrigerator. Thread marinated beef, pineapple, bell peppers and onion onto eight 12-inch metal skewers, then brush with leftover beef marinade.

If cooking on gas grill, turn all burners to high, cover and heat grill until hot, about 15 minutes 300+˚F. Clean and oil cooking grate. Place kebabs on grill and cook with cover down turning occassionally as needed until lightly charred on all sides. Meat should reach 135˚F for medium done, about 10 to 12 minutes. Transfer kebabs to  a platter and tent with aluminum foil and allow to rest for 5 minutes.

If cooking on charcoal, open bottom vents. Light large chimney starter filled with briquets. When top coals are partially covered with ash, pour over grill. Set cooking grate in place, cover and open lid vent completely. Heat grill until hot, about 5 minutes and then cook as you would on gas grill.