Preheat your oven to 350°F (175°C).
Sift together the cake flour, 3/4 cup of the sugar, and salt.
In a large bowl, whisk the egg whites until frothy.
Add cream of tartar and continue whisking until soft peaks form.
Gradually add the remaining 3/4 cup of sugar while whisking until stiff peaks form.
Fold in the flour mixture gently using a spatula.
Mix in the vanilla extract and food coloring until just combined.
Pour the batter into an ungreased tube pan.
Bake for 35-40 minutes or until the cake springs back when touched.
Remove from the oven and invert the pan immediately.
Let the cake cool completely before removing it from the pan.
Gently run a knife around the edges to loosen and remove from the pan.