Mise en place. Make sure cream cheese has sat at room temperature at least 20 minutes.
Pour 4 cups of Rice Chex into a medium bowl. In a large Ziploc bag, mix 1/3 C. of powdered sugar and 1/3 C. of dry red velvet cake mix.
In a small bowl, heat 1 C. white candy melts for 30 seconds at 50% power in microwave. Stir (even if nothing is melted). Continue heating at 15 second intervals at 50% power, being careful not to overheat. After chocolate is melted and smooth, stir in 1 oz. of cream cheese. Mixture will become extremely thick...just continue mixing until well blended.
Using hands, work chocolate mixture through 4 cups of Rice Chex. Add coated cereal to Ziploc bag that has mixed powdered sugar and cake mix. Toss, breaking up any large chunks until everything is well-coated. Spread out on a cookie sheet to dry.
Repeat steps 2-4 with both pink candy melts and red candy melts.
After everything is dry, shake out any excess powdered sugar. Mix three colors and toss with M&M's. Serve.
**Store in fridge if not eaten immediately. Due to cream cheese, this cannot be stored at room temperature for a long period of time.