Replacement won't come painted at all.
They painted it one colour to save time/money and hoped you wouldn't notice, or perhaps they didn't notice.
Is the arrowhead stuck on top of the bumper or is it countersunk like the stock bumpers?
That's the easiest way to tell if its an aftermarket or GM bumper.
The paint alone would be reason to find a new shop.
If they will let someone leave their shop with that poor of a paint job, they're not going to fix it any better, nor do you really want them to paint the lower section for you.