I have only worked with fondant once and it was mmf... I would like to make a carpenter cake using planks, hammer etc.. my question is when using mmf how and when do u change the coloring.. I need a little brown, gray, and black.. I know this is probably a stupid question... but ccers always help us in need. Thanks!!!

I'm new with it too, but I just flattened out some MMF on my mat and then put a little color in the middle and kneaded and worked it with my hands until it was uniform.

I got a good orange, black and pink this way just using Wilton gel colors (but red powder color mixed with lemon yellow gel to get my orange)...

If you have to make a large piece of 1 color you need to make small pieces of that color then need them together.
You could also paint fondant if you don't want to mix it in.

Wish there was a easier way, but you have to keep adding color & kneading untill you get the desired color. Unless you have an airbrush then you can just spray it. That's my next investment.

the easiest way i have found is to add color to the melted marshmallow, especially when making dark colors in large amounts. HTH..

My KA will pull fondant-- almost until the very end. (It did overheat once, but recovered.) If you need a lot, that works well. If not, add and knead, as everyone said. Our next invention needs to be a tiny, very powerful KA for this purpose.