How much pink food coloring is needed before turning a cake red?!
Pink food coloring will not turn red.
If you use a lot of pink food color you will continue to get pink although the more you add the darker the pink will be.
You can use beet juice.
You can use more cocoa and make sure that the liquid you use is an acid, buttermilk, yogurt or sour cream. The acid will react with the cocoa making it more red in color but it will not be a dark, vibrant red that you are probably hoping to get.
unless you put about triple the amount and cocoa powder, it most likely won't turn red. Go buy some red or add beet juice or something deep red.
does your recipe call for coca? you might can use coca to help darken the pink
Just double it
Sorry for the short answer