As in the title. I've noticed several PCBs of mine have vias which are not plated - they do not have a characteristic "gold" shine to them. I suspect this is because I was pushing the limits of drill sizes - my fab specifies 12 mil and I used 15 mil (20 mil including plating.) I've checked a few with a multimeter and they do have continuity, which is good, but I've only checked a few, so have no idea if there might be a few dodgy connections because of this. Is it something to be concerned about? Board passes DRC as specified by fab.

I've seen quite a few high density boards like motherboards and graphics cards without plated vias.

Here's an older board of mine which shows a similar problem to my newer boards. Note that some vias look gold, while others don't look plated at all.

![enter image description here](https://i.stack.imgur.com/2hcgU.jpg)