I think there should be several options for the highlights over the characters.  You should be able to change the brightness or opacity of the highlights, you should also have several color options.   You should also be able to play with color options.

 right now all good guys are green, all bad guys are red.  You should have bad guys be a certain color, and then maybe players be a different color as well. 

You may want all players to be colored based on their player color, so that way minions are distiguishable between players. So an assasin can focus fire on 1 particular player and his guys.

You may want all bad guys be the same color, but good guys be seperated into different colors based on the player's color.  So if two people are both the same generals(lets say Bob and Jill), you can tell if that is the guy you are looking at Bob's minion or Jill's minion.   This helps a healer stick to healing his best friend, rather that AI player or some other dude who happens to be the same demigod/minion

There should be opicity options, like I mentioned.  Some players will want a very bright and apparent outline of characters, while others will want a barely visable glow over the characters.  There should be different levels of opaticy for both the outline and the blanket color seperatly if possible.  So you could have only an outline, or only overlay (or some mix, like a faint overlay with right outline, or faint outline with bright ovelay)