If you make your own icing, add powder food color (in your case red) to the powdered confectionery sugar, mix thoroughly then add the liquid. You will have the best red icing you’ve ever seen using very little food color. If you add it after you you’ve add in the water or milk it will take more red food color and your icing will taste bitter. It’s a chemical thing so remember powder with powder. This works for all the deep dark colors even black.
