It's not super fancy and that's because I'm lazy. Several people have asked me for a coloring tutorial of some kind, but I really don't want to make one. Mostly just because I just make stuff up all the time so I color almost every piece differently. So I took a bunch of screenshots while painting my most recently submitted portrait of Yoi and maybe this will still help some people grasp my thought process when I'm drawing. If not, it's okay because I don't either.
I've also created a tutorial on how to add color using gradient maps.