For Black iPhone: Black vs Red vs White Case?

I'm planning to get the Mophie Air for iPhone 5.
If I have a black iphone, would it look better for the black iphone to be inside a black or red or white case.
Plus, the red case gives all 100 dollars to Product RED (African AIDS, Malaria, etc.)
So which case color?

Red.It'll help the poor guys back in Africa! Black will blend with the iPhone. Wouldn't choose that. White… Well… Thats a good color, but I think Red would help benefit people the most.

Red.