Coat 12" skillet with cooking spray and heat over medium high. Add bell pepper and green onions. Sauté until tender, about 3 minutes, stirring often. Transfer to large bowl.
In separate bowl, mix cornmeal, flour, seafood seasoning, and cayenne and set aside.
To bowl with cooled peppers, add crabmeat, frozen corn, parsley, mayonnaise, egg whites, whole milk, and lemon juice. Add cornmeal mixture from step 2 and mix until just blended.
Lightly coat 12" skillet with nonstick cooking spray and return to medium heat. Spoon four individual 1/2 cup measures of crab mixture into skillet. Using spatula flatten each into 1/2" thick patty. Cook 3 minutes per side, remove to a plate and keep warm.
Remove skillet from heat and again lightly coat with nonstick cooking spray. Repeat Step 4 with remaining crab mixture.
Sprinkle salt evenly over crab and corn cakes and serve with lemon wedges.