To paint, or NOT to paint

[Malaboge@AOL.COM]

I know this will bring out the zealots from all camps...but, what is the 
opinion of whether or not to paint brake calipers?
And if the opinion is for paint, should it be black or white?

My first thought are to leave them natural as that will probably allow the 
most heat transfer to the air, but they will probably end up rusty and is 
that better or worse? 

Never a black or white decision...
         Nick of Nor Cal