In a stand mixer, whip heavy cream and vanilla together until you receive stiff peaks. Add in sweetened condensed milk and mix until combined. Separate this base ice cream mixture into 4 bowls.
Tint one bowl of ice cream base mixture with a few drops of the neon pink icing. Mix until you reach the desired color. Repeat with the other bowls and colors (pink, blue, purple, orange, yellow & green).
Spoon color mixtures into a loaf pan, alternating spoonfuls of different colors.
After all of the colorful mixtures are in the loaf pan, use a knife to run through mixtures in the pan to swirl all of the colors.
Add rainbow sprinkles, then freeze overnight or until frozen.