16 new reactions, one for each colour, and 1328 new materials for all the varieties of painted stone, plus adding reaction product tags to all existing stone. If anypony wants to look at how the woodpainting works and adapt it, I'll include it, but it's some pretty tiresome busywork when I've got more interesting things to get working. The main problem with the current paint system is getting hold of dye plants, and there needs to be some underground. I'll probably move a few existing ones underground, like clownsbane. I'd probably also want to include magma-safe paints if I was going to include painting stone, and that's beyond DF's tech level and sensible boundaries of magic.