I actually prefer the black callipers and I think a back flag will look good too...but just a pity there won't be many of them on show.
I think the red calipers just show it off a bit better, but that is obviously down to personal preference, and there will probably be a pretty even split on here..
However, I absolutely believe there should be AT LEAST 2 flags, probably 3, in either original OR black.... Front grill, Boot and Steering Wheel.. Trouble is, I can't seem to find one online anywhere to put one on the boot myself, as from what i can see, they've only ever done the black one on the grill, as the R had a hybrid flag/R badge... I did see one, but it looked like a dodgy reproduction..