I just bought my first bbag in camel and I decided to splurge and get a wallet too. I didn't want them to match so I got a black wallet (the "money" wallet, not the zip around compagnon).
It sounds strange maybe to some, but put together they go quite nicely. And it will look fine with any other color.
However, if the store had had some bright funky colors (I'm still afraid to venture outside of neutral territory) I may have gotten one. Would be nice to play with the accessories' colors and keep it safe (for me) with the actual bag. Next time, right?
By the way, though the wallets are pricey, they're also really nice, in my opinion. Well designed for me, I don't need a complicated wallet, and very chic looking with a bit of edginess. Perfect!