Line 8-inch square pan with aluminum foil, extending foil over edges. Butter foil; set aside.
Combine sugar, butter and evaporated milk in 2-quart saucepan. Cook over medium heat, stirring constantly, 6-7 minutes or until butter is melted and mixture comes to a full boil. Continue cooking, stirring often, 5 minutes. Stir in marshmallow crème and 1 teaspoon vanilla. Remove from heat.
Spoon 1 1/2 cups hot mixture into bowl; stir in 3/4 cup chocolate chips until smooth. Spread into prepared pan. Place into freezer 5 minutes or until set.
Add white baking chips and remaining vanilla to remaining marshmallow crème mixture in saucepan; stir until smooth. Spoon 1 cup mixture into another bowl; add enough food color to for desired orange tint. Stir in orange zest, if desired.
Remove chocolate mixture from freezer; spread orange mixture over top. Return to freezer 5 minutes or until set.
Remove fudge from freezer. Microwave remaining marshmallow crème mixture in bowl 10 seconds or until soften, if necessary. Spread over orange layer. Sprinkle with decorator sprinkles. Refrigerate 1 hour or until set.
Remove fudge from pan using foil ends; place onto cutting surface. Carefully peel off foil. Cut fudge into 36 squares. Cut each square in half diagonally.
*Substitute 2 (4-ounce) white chocolate bars, chopped.