Rise Flashcard Slider Progress - Font Color

I put a dark background under my flashcards in Rise 360, but I'm unable to change the font color for the slider progress unless I change it in the elements area. Unfortunately, my element change doesn't stick when publishing the course.

Attached are the before (Flashcard Slider Issue_v0) and after (Flashcard Slider Issue_v1) pics (that is, after changing the element). Is there a way to change just the slider progress font, or can this be configured to allow the user to choose the font color for this element in your next update?

Thank you.