the paint would match better if it was installed before and the entire bumper was repainted, but otherwise it would be easier and cheaper to paint prior to installation. $100 US should cover it nicely.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>