In a small saucepan, set over medium heat, add the strawberries, sugar, water and vanilla extract. Cook for about 5 to 7 minutes until softened. Smash with the back of a spoon. Transfer to a food processor or blender and puree. Pour through a sieve, into a bowl and set aside. You should end up with about 2 to 3 tablespoons of puree.
In the bowl of a stand-up mixer with the whisk attachment, add the egg whites and sugar; beat just until combined. Add a few inches of water to a saucepan and bring to a simmer. Place the stand-up mixer bowl atop the saucepan, creating a double-boiler.
Heat until the mixture reads 160 degrees on a thermometer and/or until it's very hot to the touch. Transfer the bowl back to the stand-up mixer and beat, on high, for 8 to 10 minutes until medium to stiff peaks form. The sides of the bowl should be cool to the touch. Remove the whisk attachment and in place of it, add the paddle attachment.
While the mixer is on low, add the butter, a tablespoon at a time, until it's light and smooth and fluffy. Lastly, add the 2 tablespoons of strawberry puree and mix until combined. If the frosting is soupy (mine was because it was really hot), add the bowl to the fridge to chill for 5 to 10 minutes. This will work like a charm. Divide the frosting into 3 (adding a tablespoon or two more to the first bowl). Keep the first bowl (with the most frosting) free of coloring. To the second bowl, add 2 drops of red food coloring and mix until thoroughly combined. To the third bowl, add 4 drops of food coloring and mix until thoroughly combined. You should end up with three bowls that have an ombre effect. Set aside.