Cook pasta as directed on package. Rinse under cold water; drain well. Mix mayonnaise, sour cream, salt and pepper. Set aside.
Place pasta large bowl. Add vegetables and dressing; toss gently. Cover.
Refrigerate until ready to serve. Just before serving, add 1 to 2 tablespoons milk, if desired, for creamier dressing. Stir in Salad Toppins.