The modern solution to this is to have the car "wrapped". It sounds crazy, but it's a vinyl film which is applied to the entire car. A company can make it virtually any colour you like, and the job on a small car like the mini would cost about £1,200 and be done in a day.
The beauty of it all is, as soon as you are bored, you can just have the wrap peeled off again, and your original paint is restored exactly how it was.
I have been amazed about just how good wrapped cars look in the flesh. I wouldn't consider respraying a car these days when wrapping looks as good as it does, and can be done in a day.