Grey one looks the nuts. Gunmetal grey is my fav colour of all time. Ferrari and lambo's look awsome in that colour.

Anyway, I like the Rs in red, it is different (I haven't seen one) .. As for resale value, who cares.. I own a car to enjoy myself and not the next owner. I don't really care if it drops a few quid in price. If the bodyshop do a good enough job I'm sure it will be a sought after car when / if you sell it on later. I would rather have a decent colour change car than a bodged under bonnet job.