So my DIO has a dark black scale on her side, behind her arm. I just noticed it as I was giving her a bath. I gently rubbed it and she had the kick/swipe away reaction Beardies tend to have if you touch one of their sensitive shed areas.
Also of note, I am bathing her (again) because she has not pooped for what may be past two weeks now. She is also being a picky eater.
I will need to keep a close eye on it, but after the bath it seems to have faded in to match DIO's natural black/grey coloration's. It is not out of the question that it is normal and i've just never noticed it before.
I finally managed to get her to expel her stink demons... in the horrifying "exploding ball of poopy mist chunks" rather than a single few pieces!