What if players could create fan-made skins/parts and upload them to the skin editor or something similar? Here's an example:
>Player #1 makes very good helmet that fits in PB.
>Player #1 presents helmet to DoomWrath or another admin.
>DoomWrath uses admin powers to upload .png to the Skin Editor database.
>Helmet is available to all players.
> (Optional) Credits can be given to Player #1 for creating the helmet.
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I'm not entirely sure how it would work with recoloring, but I think this idea could be a cool way for the community to contribute to PB2.5.