This ElvUI is general purpose, but the health bars are set away from the screen, it tracks the target's aggro and changes color according to that aggro.
Green: Has aggro
Yellow: Neutral
Red: Aggressive (You have no aggro)
Orange: Losing aggro
It also shows enemy casts larger than individual ones so you can see them better and interrupt them.
Black: Interruptible
Red: Not interruptible