I still don't know what the rule of thumb is with food coloring but in this case my thumb may as well had been up my ass. I wanted to make them more than just sugar cookies. Well, mission accomplished...I made an ass out of myself and my friends who ate them as they all ended up with the brightest mouths you have ever seen. Blue, green, red...It was like pens exploded in their mouths. I'm guessing it has to be cooked or settled or have a spell cast on it or just be kept away from me.
The times I have used it successfully have always been in something that has been baked or when a minimal amount has been used in a frosting...a lesson learned the hard way by my friend Kristin whose 1 year old sported a red stained face for days after an overly aggressive take on a bright frosting for a giant cupcake. Kristin, you made me feel better with that one. I dyed my friends' mouths. You stained your baby's face.