Paint chipped underneath laptop?

[leesiulung]

So upgrading my hard drive I noticed a spot that didn't have black paint. It is located underneath a screw on the chassis when you remove the hard drive plastic lid. Just look where the screw would go, but look on the chassis. On my there were a circular grey spot with no black paint on it. Is it suppose to be like that?

I was very careful when I opened it and did the upgrade.