Amarante Vernis!! This colour is so rich and sumptious - it would make the key-holder a fantasic piece of eye-candy, plus, with it being dark, it should be amazingly resistent to colour transfer + general wear and tear.
...Personally, I own the key-holder in Framboise, and despite using every day for the past 4 months it still manages to look as good as the day I bought it. So yeah, vernis gets my vote!!
Vernis Pomme!!! I don't like Amarante because it's a fingerprint magnet. I love my vernis pomme so much until I went to get a vernis pomme french wallet as well a couple of weeks later.