It seems to me that this would allow the healer to watch the field of play and actually enjoy what’s going on while healing.
It keeps healing challenging because the healer has to watch the field of battle, but also allows them to watch the fight and use their peripheral vision to monitor group mates in their field of view, which combined with the fact that players might run out of line of sight, thus encourages good group communication and coordination.
I don’t imagine you could do this in WoW raids as they stand, but LotRO raids might be feasible, and a new game could develop their combat system with the idea in mind, using systems such as non-targeted cone and PBAoE healing, as in AoC, to make healing an experience where the player is engaged in the game world as much as other classes, rather than standing still and playing health bar whack-a-mole before shifting to a different standing spot when the pool of fire/green goo/ice/dark matter appears near them.
And if nothing else it will lead to a whole new area of MMO slang:
“I’m down to my bum in health!”
“I’ve got a foot’s worth of health left!”
“Oh stop complaining, I don’t need to heal you, you haven’t lost more than your head so far.”
I’d imagine that you could have the ‘empty’ colour be configurable, as I’m sure colour blind people manage to deal with health bars doing the same sort of thing. Either that or have characters turn translucent as the colour drains out of them.
I fear that with twinkling we’d be accused of attempting to Twilightify MMOs. Or is that sparkling? No, no, that was ponies wasn’t it?
Lordy, imagine the Twighlight-vampire-sparkling-pony, if you dare.