Preheat the oven to 350°F and place a rack in the center.
Soften the cream cheese at room temperature for 30–45 minutes.
Drain the crab meat for 3–5 minutes and remove any shell fragments.
Finely dice the red bell pepper and slice the green onion.
Mix the cream cheese, sour cream, and mayonnaise until smooth.
Stir in the lemon juice, Worcestershire sauce, seafood seasoning, garlic powder, onion powder, and cayenne.
Gently fold in the crab meat, vegetables, ¼ cup mozzarella, and Parmesan.
Spread the mixture evenly in a 1-quart baking dish.
Sprinkle the remaining ¼ cup mozzarella over the top.
Bake for 18–22 minutes, until hot and bubbling around the edges.
Broil for 30–60 seconds for a lightly browned top, if desired.
Let the dip rest for 5 minutes before serving.