Gotta go to the BBB, consumer affairs and any other advocacy group you can find. Point to this form. Get your dealer manager and GM involved.
Make enough noise to make it no longer worth their time or negative publicity to fight you on it.
You can get it handled, but you have to be the squeaky wheel. Having the entire truck's paint mismatch is a serious flaw and having the entire truck repainted or even half the truck repainted severely impacts the value of the vehicle.
The thing is, if they do a buy back on your truck, they'll just turn around and sell it to someone else without ever doing any repairs. Someone will take it and never even notice it. So it's not really costing them a thing.
My truck showed up on my dealer's lot a week or so after they took possession of it. They just pawned it off on another unsuspecting customer.