Combine butter, confectioners sugar and salt in the bowl of a stand mixture. Starting on low speed, use the whisk attachment to slowly incorporate the sugar into the butter.
Once incorporated, add the vanilla and whipping cream and beat on high speed until the mixture is light and fluffy, about a minute.
Remove a quarter of the mixture and place in a separate bowl for the blue frosting. Remove one third of the remaining frosting and place in another bowl for the red frosting. The remaining white frosting will be used to frost the white cupcakes. Place a small about (about 1/4 cup) of the white frosting in a piping bag set with a small white tip. Transfer the remaining white frosting to a piping bag fixed with a large blunt tip.
Dye the red and blue frosting as follows:
For Blue Frosting: Mix 12 - 14 drops of Wilton Color Right Food Coloring System Blue into the icing and mix until completely combined. Transfer frosting to a piping bag with a large blunt tip.
For Red Frosting: Mix 14-16 drops of Wilton Color Right Food Coloring System Red into the frosting and mix until completely combined. Transfer frosting to a piping bag with a large blunt tip.