I tried to find a post about this but I couldn't see one.
but the part labeled Iris is actually the pupil. Its actually the portion around the pupil that's called the Iris.
I think you should leave the pupil as color changing but include color changing for the actual iris as well.

Eye Diagram

hmmm idk i love the way they are. i think the black/dark pupil is like her brand you know? it's what makes bot BE bot xD but yeah, having the option would be cool.