Prepare Base: Heat the heavy cream, milk, and sugar in a saucepan over medium heat. Stir occasionally until the sugar dissolves, about 5-7 minutes. Remove from heat and stir in the vanilla extract. Allow the mixture to cool completely.

Make Raspberry Puree: In a blender, blend the raspberries with 2 tablespoons of sugar until they form a smooth puree. Strain the mixture to remove any seeds for a silky finish.

Churn Base: Once your base has completely chilled in the fridge, pour it into the ice cream maker. Churn until it reaches a soft-serve consistency, which usually takes about 20-25 minutes.

Create Flavors: Divide the churned base into three separate bowls. For the Orange Flavor: Mix in the orange juice, zest, and optional food coloring. For the Lime Flavor: In another bowl, combine the lime juice and zest. For the Raspberry Flavor: Fold in the raspberry puree to the last bowl.

Layer and Freeze: In a freezer-safe container, alternate spoonfuls of each flavor. Use a knife or spatula to swirl them together gently for a marbled look. Cover and freeze for 4-6 hours until solid.