Melt the white chocolate chips and frosting together in a double boiler (or a glass dish over a pot of water).

Stir them every minute or so, and cook for about 8 minutes or until the mixture is smooth.

Divide the mixture between 3 bowls, mixing red food coloring into one and green into another, leaving the last one white.

Line an 8-inch square baking dish with parchment paper, allowing some to overhang the sides.

Dollop the 3 different mixtures into the dish, then use a butter knife to swirl them together.

Refrigerate for an hour or two, uncovered, until set.

Cut into pieces and enjoy.