Preheat oven to 400 degrees. Spray an 8x8 or 9x9 baking dish with nonstick cooking spray. Chop the shrimp into small piece. Blot shrimp dry with paper towels and squeeze excess moisture from the crab and shrimp. In a large mixing bowl, combine cream cheese, sour cream, mayonnaise, cheddar cheese, bell pepper, green onion, Cajun seasoning, and lemon zest, Fold in shrimp and crab. Pour into baking dish and top with Colby jack cheese. Bake for 25-30 minutes or until cheese is melted and bubby.