Is this possible? I've never used this stuff, got a bag of it, but it's clear. I'd like to not have to buy something like powdered paint as I've already got a shit load of gel food coloring and would prefer to use what I've got. Any answers would be appreciated. Thanks
-d

It'll work- but there's a real chance it'll stain your hair/skin/clothes. Try a small test batch first before you cover yourself in it.
(Children's poster paint/Tempura paint is the safest option I know of as its designed not to stain, and sometimes still stains clothing even when washing it immediately after a messy session).

It depends a lot of how much colour you mix into your batch.

You think there'd be a difference with how it reacts with the methylcellulose vs our pies that we dye with the same food coloring? We haven't had issues in the past coloring cool whip and slime, but idk if the methylcellulose would act different as a base to hold the dye compared to the cool whip/cake batter.

I've had no issues mixing methyl with other substances. As for clothing, stick to synthetics only. Dye or mud, etc. tends to wash out much easier than natural fabrics. Magnify a cotton thread and it's full of pores and cells where a synthetic fiber is more like a solid plastic.

I made the mistake of using green food colouring many years ago when i first tried making slime. I was using Xanthan gum instead of Methylcellulose, and luckily for me I only made a small batch, enough to cover my feet, not my whole body. But sure enough, after washing off, my feet had a slight green tinge to them. It took around 10 showers over the next 2 weeks to completely wash away. I wouldnt even use food colouring for full body coverage. Switched to poster paints and have used them ever since without any problems at all

If you really want to use up your food colouring, do some test spots on hideable parts of your body first and see how it goes, before covering any exposed parts such as your face or hands