Line 15x10x1-inch baking pan with foil so foil extends over sides of pan. Grease foil. In large saucepan, combine sugar, butter and evaporated milk; cook and stir over medium heat until sugar is dissolved. Bring to a full boil, stirring constantly. Boil 5 minutes over medium heat without stirring.
Remove from heat. Add marshmallows, stirring constantly until mixture is smooth. Remove 2 cups mixture; place in medium saucepan. Set aside.
To mixture in large saucepan, add chocolate chips, unsweetened chocolate and vanilla; stir until chocolate is melted and mixture is smooth. Quickly spread mixture in greased foil-lined pan.
Add white chocolate, peppermint extract and green icing color to reserved mixture in saucepan; stir until chocolate is melted and mixture is smooth. Pour evenly over fudge in pan; spread gently to cover. Sprinkle with chocolate sprinkles. Refrigerate 2 hours or until firm. Remove fudge from pan by lifting foil. Cut into squares.