A silver one
I'll take some now with my second iPhone (like a boss)
EDIT:
Well here's mine anyway, they can call it "dirt ingress all they want, but I was pretty hot on keeping mine clean.
I just don't think it's acceptable that something which is supposed to protect the phone, damages it.
Looks like you've taken a picture of my phone there! Will Apple polish it for you!
No bumper or case FTW.
Don't hide the sexiness.
Eh? You raved for 12 months "Black 32gb White Apple Bumper"!