DC_Roenfanz pointed out the easy fix was to set the DynamicData of a seperate health bar to ProgressBar with the darker image and filter out the the Progress percent with a DynamicFilterData="FFBF" to simulate color changing background bars..
I'm doing it slight differently by using an Image object instead of ProgressBar.. And just setting the DynamicData.. I had already put them in..
I'd rather deal with one object instead of two.. But, ohwell
And, from what I've read here, I do not believe this will work in the group window because the dynamic data isn't pushed yet..