Place cakes in freezer for 20 minutes. A cold cake is much easier to frost.
Add all 6 tubs of frosting to the mixing bowl of a standing mixer, and beat the frosting for 1 minute until it is light and fluffy.
Place a half cup of frosting each into two small bowls (1 cup in total). Mix the pink food coloring in one bowl and the red food coloring in the other, until the frosting is the desired shade.
Using a board (any kind will do: cutting board, charcuterie board, etc.), place a dollop of frosting on it. This will act as an adhesive to keep the cake in place and prevent it from sliding around.
Place the first cake layer on the board and spread 1 ½ cups of frosting over it. Make sure the frosting is even. Then, place the second cake layer on top and frost it just as you did the first. Finally, place the third layer on top.
Apply a light layer of frosting to the entire cake and freeze for 15 minutes. This locks the crumbs in place and prevents them from getting into the final layer of frosting.
Remove cake from freezer and add the final layer of frosting.
Decorate the cake with small hearts using the pink and red frosting. To form a heart, pipe two slightly diagonal lines in the shape of the letter V. The lines will be separated slightly at the top but come together quickly at the bottom.