Prepare the pan by lining an 8-inch square baking dish with parchment paper, leaving overhang for easy removal later.

Melt the chocolate by combining white chocolate chips and sweetened condensed milk in a heatproof bowl. Use a double boiler or microwave in short intervals until smooth.

Once melted, stir to combine the mixture, ensuring it becomes silky.

Divide the mixture into two bowls; add red food coloring to one and blue to the other, stirring gently to avoid overmixing.

Pour the uncolored fudge base into the pan, dollop red and blue mixtures on top, and swirl gently.

Sprinkle star-shaped sprinkles on top and press them into the surface for better adhesion. Freeze for about 30 minutes.

Once set, lift the fudge out of the pan using the parchment overhang and cut into squares.