Spray a 9x13 casserole dish with nonstick cooking spray. Line with parchment paper and spritz the paper with more nonstick cooking spray or grease with butter.
In a large microwave-safe bowl, add 3 ¼ cups white baking chips, all of the chocolate chips, and 2 teaspoons of vegetable shortening.
Microwave the chocolate on high for 1 minute. Stir vigorously to allow the chocolate to continue melting with the residual heat. Return the chocolate to the microwave and heat in 15-second intervals, stirring well between each, until the chocolate mixture is smooth.
To the chocolate, add the condensed milk and food coloring, stirring until combined. Stir in 1 cup powdered sugar.
Transfer the chocolate to the prepared dish and spread evenly.
In a clean microwave-safe bowl, add the remaining white baking chips and shortening, heating on high for 1 minute. Stir vigorously to allow the chocolate to continue melting with the residual heat. Return the chocolate to the microwave and heat in 15-second intervals, stirring well between each, until the chocolate mixture is smooth.
Add the cream cheese and vanilla extract to the chocolate. Beat with an electric mixer until smooth. Slowly add and beat the remaining powdered sugar into the chocolate until smooth.
Transfer the white chocolate mixture to the prepared dish and spread over the red fudge layer.
Refrigerate for at least 2 hours or until firm.
Remove the fudge from the baking dish by lifting edges of parchment paper.
Heat a large knife under hot running water. Wipe dry and cut the fudge into squares, reheating and drying the knife between cuts.