Add the heavy cream, powdered sugar and vanilla extract to the bowl of an electric mixer. Using a whisk attachment, whip the cream until stiff. With a rubber spatula, gently fold in the sweetened condensed milk until combined. Divide the mixture among 3 bowls, coloring one bowl with the neon blue food coloring, one bowl with the neon purple and one bowl with the neon pink.
Layer the different colors of ice cream base into the chilled loaf pan a couple spoonfuls at a time. There is no rhyme or reason when layering; you want it to be imperfect. Once all of the base has been added to the pan, swirl the colors using a skewer or butter knife. Sprinkle an assortment of sprinkles over the top and wrap lightly with plastic wrap. Freeze overnight.
When ready to serve, scoop into individual glasses and top with additional sprinkles.