I plan on mixing my fondant with Pettinice chocolate fondant in order to cover a 16, 12 and 8 square cake. I'm afraid now that I don't have enough Pettinice to cover all of it. What else can I do? This is my first chocolate covered cake. Help!!

Make more fondant. You can save it for a time if it is very carefully packaged. However, once you start applying it, you cannot make a match with what you have already applied.

After I mix all of my fondant together and I discover I do not have enough, could I make more white fondant- add that to the rest and add brown food coloring to make it all look uniform?