I need brown icing. I have brown food coloring but I would have to use so much that I am afraid it will make the icing taste bad. The only other things I have is chocolate syrup and boxed chocolate cake mix. Will either work. I need this for a FBCT.

do you have any chocoalte chips or baking chocolate? These would work better. I think chocoalte syrup might make it too thin to work with.

I have used chocolate syrup in a pinch. Your icing must be thick, because it will thin it down. Also, it won't get dark, Only light brown.
I have used choc. pudding mix too. It does better, but leaves tiny specs of darker color, but tastes great. I am the queen of improvising. My family calls me McGiver.