I felt the same way about seeing the Z in person. Feels a lot like the rest of the recent Zs (350/370). it's definitely nice. The rear end I think is decent, but I felt like it was generally boring.
The cars I thought really brought some juice, were the Lexus. A couple of cool production cars...
I have a bunch from the Chicago Auto Show mid-last year. It was pretty underwhelming because many of the manufacturers didn't show due to COVID protocols. Hoping this years will be a better event.
Ever try to touch up a little paint on a wall in your house. Environmental conditions, age of the paint, quality of the painter, differences in brushes, etc. It's never exact.
Same goes for cars,
A full bumper repaint is probably the way to go for this, but it's a little hard to say. If they repaint the whole bumper you run the risk of it not quite matching the rest of the car.
If it were me, I'd paint the whole bumper.