On my blue Tourer (Seafrost - JYA) there’s a slight but fairly obvious difference in colour between the bonnet and the rest of the paintwork. Here’s a link to a photo although, to be fair, it does make the difference appear somewhat greater than it actually is. Still, it’s enough to be quite annoying!
https://www.icloud.com/sharedalbum/#B0V5oqs3qSp0GX
It would surely be rather unusual if the car had been in an accident such that only the bonnet, and none of the other panels, had to be replaced or resprayed, although I guess it’s possible that something dropped onto the bonnet from above at some stage!
I have T-cut and polished the bonnet just in case it had weathered differently from the other panels by being horizontal, but this hasn’t made any difference.
So is this a factory quality control issue and, if so, is it a common problem? I’d be intrigued to hear any other ideas.