Whisk together BBQ sauce and pineapple juice in a small bowl.
Place chicken in a sealable plastic bag or other container and pour half the BBQ mixture on top and reserve the other half for later. Toss to coat and let marinate for 2 hours up to overnight.
Thread the marinated chicken, peppers, red onion and pineapple onto skewers repeating until each skewer is filled.
Preheat an outdoor grill over high heat.
Once hot, lightly brush each skewer with canola oil and place on the grill.
Cook about 4-5 minutes per side until grill marks appear and chicken is cooked through.
Remove from grill and brush with the reserved BBQ sauce mixture.