I made a suggestion on identifying players from longer distances a while back.
I do not think skins fit in a survival game at all. Not only does it look ridiculous and out of place, but it also ruins a big aspect of the game. As a survival game you should be able to look at a player and observe what he is wearing and holding in his hands, as this would play a big factor in wether or not the casual player would like to engage the player or not. Seeing a player running around in a full santa costume with skinned weapon and a bunch of effects, does not only look ridiculous, but its also unbalanced. You would never know what the player is actually wearing/using.