What is used to color the Plastisol? Do I use regular food coloring?

I’ve not tried to color Plastisol. My research indicates that food coloring might not be the best choice. My reading suggests using an oil based paint rather than a water based product. Still, I’d try the food coloring first and if you don’t like the end product, you might want to read here or here to further your knowledge. Enjoy your project as I’m sure you can decide what works best for you