I'm with Trellis on this one, Milano Red, on my 1.4EX I-shift, as it's the only colour in the UK that you don't pay extra for.
Also, I like my car to be seen by other roadusers, when I'm driving. I find that colours like silver etc, tend to blend in with the road surface in poor weather conditions and are difficult to see at a distance.
I remember many years ago, my first brand new car was a Austin Metro, in yellow! as at the time, the UK fire service was thinking of changing the colour of their fire engines, from red to yellow, supposedly because red didn't show up very well under sodium street lights.
Of course it never happened!