In a game, called Rome total war, there are about 20 factions, and i started to wonder, how come i could see who was who, and how did the gauls differ from the turks? Well, what i started to see was custom banners, with symbols on them. Those of wich also could appear on the minimap i thought.
So, what i suggest is that maybe we here at glest, could implement such a thing as "Banner team colour"? This means that there can be two different purples, but on got a silver eagle symbol in it, and another one has a golden sword. You could then easilly tell the difference between factions. Have a look at the different symbols for different factions in the total war series and you get what im rambling about