Question about "Paint to Match" car parts.

I just bought a replacement side view mirror for my car online and it was advertised as Paint to Match. I couldn't find a ton of details on the product. Does this mean that it comes completely unpainted? If so, are there any laws against having car parts without paint/unfinished? I don't want to spent the extra time/money to paint it and I don't care at all what it looks like, but I want to make sure I won't get pulled over for it or something like that.

I don't know if this is the proper subreddit for this. If not, please point me in the right direction.

Thanks!