In a bowl, toss together the 1/3 cup bread crumbs, green bell pepper, red bell pepper, green onions, and parsley. Mix in the egg white, mayonnaise, lemon juice, Worcestershire sauce, and Dijon mustard. Season with Old Bay seasoning, dry mustard, and onion powder. Fold crabmeat into the mixture. Form into 6 large cakes. Coat in the remaining 1/2 cup bread crumbs.
Heat the oil in a large, heavy skillet. Fry the cakes 5 minutes on each side, or until evenly brown. Drain on paper towels.
