Depending on the quality of care your paint work has register in the past, you could find your paint has faded etc....
That's why the touch up isn't exactly the same colour!
It would be an idea to talk to revolution to see about a protective film for when you have it back the way ya want it, but honestly the best way to cure the problem with out being able to see it everytime you look at the car is respraying the bonnet properly again