I've always thought one of Buffy's main characteristics was her ability to improvise and adapt.
Oh definitely. I just don't think she'd *like* to wear those outfits, and I'd like something to reflect that. That's all. One little line - wouldn't kill anyone, would it?

That said, it looks like the set-up might just be a 'things are wrong' kinda deal - Buffy and Gigi in their respective castles, each with their magicians etc and isolated from the world... (I have no idea if this is correct. I claim no insight where s8 is concerned.)

(And maybe going green is a side-effect of being in hell?)