In large bowl, cream butter and sugar with electric mixer until light and fluffy. Add eggs, icing color and vanilla extract; mix until icing color is well incorporated, scraping down sides of bowl when necessary. Alternately add flour mixture and buttermilk. Mix until just combined. In a small bowl, combine white vinegar and baking soda; gently stir into cupcake mixture. Divide batter evenly among prepared pan cavities.