Natural wood will make it look more like a piece of furniture. I recommend this method if you have other natural wood furniture. You can get some stain and try and match your furniture so it goes well with your decor. This might make your wife happy.
Black looks "cool" your buddies might go "wow, man cool arcade". Black has been done to death. It is too safe. NOTE: I am making a black and blue cab - even more cliche'
A bright color would have more style and be more fun like a real arcade. I wish I didn't pick the standard black/blue button combo. I remember all sorts of arcade games where every button was some different wacky color. Orange, yellow, blue, green with no coordination at all. Thats what classic arcades are all about LOUD FLASHY sounds and colors.
bottom line, choose what YOU really want (or what your wife wants) Because we're not going to come over and play your cabinet and I'd bet most of your friends and family don't read these boards.

I say orange or Yellow with orange T-molding. I wish I had been that brave