Line a 8-inch square pan with parchment paper. Remove the top from one can of sweetened condensed milk and stir in the pink food coloring until the milk is bright pink in color.
Pour the pink condensed milk into a medium saucepan, with the white chocolate chips and butter. Cook over medium heat, stirring frequently, until melted and smooth.
Scoop the pink fudge mixture into the prepared pan and spread with a spatula to cover the bottom of the pan evenly. Allow to harden completely before making the red layers.
Remove the hardened sheet of pink fudge from the pan and peel off the parchment paper. Set aside. Place a new piece of parchment paper in the bottom of the empty pan.