Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the penne, and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through, but is still firm to the bite, about 11 minutes. Drain well in a colander set in the sink. Rinse with cold water to stop the cooking process.

Combine the mayonnaise, salad dressing, Italian seasoning, garlic powder, cayenne pepper, salt, and pepper in a blender; blend until completely mixed.

Place the coleslaw mix, tomatoes, cucumber, tuna, Cheddar cheese, Monterey Jack cheese, green onions, and the cooked pasta in a large bowl; pour mayonnaise mixture into the bowl; toss to coat. Serve cold.