Place peppers, onion and garlic in 4-qt. slow cooker.
Toss chicken pieces with flour to coat, shaking off and reserving excess flour.
Place chicken over vegetables in slow cooker.
Drain diced tomatoes. Stir together drained tomatoes, tomato paste, balsamic vinegar, Italian seasoning, salt, pepper and reserved flour; pour over chicken.
Cover; cook on low until chicken pieces are tender, 8-10 hrs.
Skim and discard fat from slow cooker.
Stir in capers.
Place pasta on serving platter; top with chicken mixture.
Garnish as desired.