Preheat oven to 350°F. Line 36 muffin cups with paper baking cups.
Mix flour, cocoa, baking soda and salt in medium bowl; set aside.
Beat butter and sugar in large mixing bowl at medium speed until light and fluffy. Add eggs, one at a time, scraping down sides of bowl with each addition. On low speed, add sour cream, milk, vinegar, vanilla and food coloring. Slowly add in flour mixture and blend until just combined. Do not overmix. Fill muffin cups 2/3 full.
Bake 20 to 25 minutes or until cupcakes spring back when touched. Remove from oven; cool completely in pan.