In a large bowl, stir together potato soup, sour cream, and cream cheese.
Stir in ham, green onions, salt, pepper, garlic powder, hash browns, and 1 1/ cups Colby Jack cheese.
Transfer to slow cooker.
Place 2 layers of paper towels on top of slow cooker and cover with lid.
Cook on low for 4 to 5 hours.
Sprinkle with remaining 1/2 cup colby cheese and the cheddar cheese. Cover and cook another 10 minutes or until cheese is melted.