Personally it would be very boring if we all painted our Cobra's blue with white stripes, or similiar original colours. (Says the person painting his GT40 blue/white.)
So the more variety the better. There are so many great manufacturer colours these days. Also you have all the aftermarket colours. The choice is endless.
One factor to keep in mind, is that if you paint your Cobra a really unusual colour that doesn't really have a broad appeal, it will be more difficult to sell. But offering to re-paint the car to the owners choice of colour on sale, certainly fixes that.
