Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with nonstick cooking spray.
In medium saucepan, combine 1/4 cup of the bell pepper, onion, water, ketchup, chili sauce, oil, salt, dry mustard and pepper; mix well. Bring to a boil over high heat, stirring constantly. Boil 2 minutes.
Remove saucepan from heat; stir in lemon juice and Worcestershire sauce. Reserve 1/3 cup sauce. Stir rice into remaining sauce. Pour rice mixture into sprayed baking dish. Arrange fish fillets over rice mixture. Top with reserved sauce, tomatoes and remaining 1/4 cup bell pepper. Spray sheet of foil with cooking spray; place, sprayed side down, over baking dish.
Bake at 350°F. for 35 to 40 minutes or until fish flakes easily with fork.