Quote from whitebrowI've never tried to setup the frames in that way. This is how I have it setup. Similar I think to what you are referring to.
Medium Health and Full Health
Medium Health and Low Health
Yeah, that would be colouring the bars based on health, which doesnt really give you an indication of class (at least not from the colour). All im after is a simple "invert bar colour" button which would probably do the trick.