Out of all the ideas so far, I think the hedge and stone Neopets have the most potential to be interesting.
Sick or injured hedge Neopets could have pieces missing and/or lose a lot of their leaves (so just sticks were showing) and/or have their leaves turn brown and shrivel up. In the battledome, Hedge pets could throw leaves in their ranged attack pose, and have leaves scatter when they got hit.
Ill Stone ones could be either cracked or just a pile of rubble. Heck, there could be spackle in the cracks instead of bandages
And they could be plain ol' carved out gray stone, like the old color was...or it could be swirled marble, layered sandstone, possibly even a faceted gemstone (though that might be too similar to Ice).
There's just so much to play with in both of those ideas. I can see why Glass got retired since they came out with an Ice color that's essentially the same thing, but Stone really should have stayed. *shrug* I guess you could say Clay is an equivalent, but they haven't really made it interesting. Maybe if it was pottery, glazed pottery/porcelain as someone else suggested, it would be better.
As for whoever suggested 'hillbilly' as a color, I don't know whether to be offended or amused by that.
I have to admit though, when I first heard of Bogshot Village, I kinda imagined this swamp with shacks in it, with ahh, rustic old Neopets living there. ("C'mon in heah, young'in! Sit a spell! Hep yo'self to some Graka Bug cassa-role!")