I thought you meant “kulah for powdered cholov stam”
I can see where the heter is, because (if I remember correctly) food coloring can be made from the blood of worms, after they are dried and crushed into powder.
Truth? The whole inyan today (IMHO) in regards to cholov stam / cholov yisroel is NOT about kashrus.
Its about following your mesorah, or choosing a path thats right for you.
So its not about a “kulah” its about doing what you feel right about.