Combine flour, cocoa, baking soda and salt in a bowl and stir well to combine. Set aside. Using a mixer, in a separate bowl mix butter until light and creamy. Add sugar and beat until well combined. Add in eggs and sour cream, mix until combined. Add in red food coloring until desired consistency is reached. Combine dry and wet ingredients, and add in buttermilk, stir until combined. Scoop batter into muffin pans that have been lined with 24 muffin liners. Fill muffin liners about 2/3 of the way full. Bake for approximately 18-20 minutes or until toothpick inserted into the center comes out clean. Remove from oven and allow to cool completely prior to frosting.