Line a 9 X 9 or 8 X 8 pan with aluminum foil, set aside.
Place semi-sweet chocolate chips and food coloring in a heat safe bowl and set aside.
In a large, heavy saucepan, combine sugar, butter and evaporated milk and cook to 234 degrees, stirring occasionally.
Immediately add white chocolate chips, marshmallow cream and vanilla, mix to combine.
When well mixed, scrape half of the white chocolate fudge into the bowl with the semi-sweet chocolate chips and mix till melted and smooth.
Using two medium cookie scoops or tablespoons, place scoops of red and white fudge n the prepared pan, alternating flavors.
Drop pan from a few inches above counter a couple times to remove any air bubbles. With a knife, swirl through the fudge to give a marbleized appearance.
Allow to cool at room temperature. Then refrigerate. When cool, remove from pan using foil and cut into squares. (This cuts easier after refrigeration)