In a large mixing bowl, combine the corn, cherry tomatoes, bell pepper, and red onion. Stir until well mixed.
In a separate bowl, whisk together the sour cream, mayonnaise, lime juice, chili powder, garlic powder, salt, and pepper until smooth.
Pour the dressing over the corn mixture and stir until all the ingredients are evenly coated.
Gently fold in the Fritos corn chips and shredded cheddar cheese, being careful not to crush the chips.
Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld.
Before serving, garnish with sliced green onions.