Lightly grease a 9x13-inch baking dish with nonstick spray.
In a large mixing bowl, combine the thawed hash browns, diced onion, shredded sharp cheddar, cream of mushroom soup, melted butter, sour cream, garlic powder, onion powder, paprika, and season with salt and black pepper. Mix well.
Transfer the mixture to the prepared baking dish and spread evenly.
Sprinkle the shredded Colby cheese on top.
Bake uncovered for about 45 minutes, or until bubbly and golden brown on top.
Let it cool for a few minutes before serving.
Notes
Make sure hash browns are thawed for better mixing.
Store leftovers in an airtight container for up to three days.