when I roll out my MMF I am having to use a lot of powdered sugar on my board and rolling pin. How do you get the residue left on the fondant off so the colors look true again?

I rub a little shortening on my hands and "smooth" the cake... Takes care of the problem.

I don't actually use powdered sugar when rolling out, I grease everything with shortening. It seems to help keep away cracks, and helps keep the colors true.

i roll my MMF out on cornstarch. It is so much easier to work with than powder sugar.

also, you can use a high alcohol liquid (some use vodka, i personally like mint extract) and a paint brush (one that you only use for food) and dab it onto the ps residue, and that helps.