They look like covers at first glance but they aren't stickered on. I've never seen pads like this and searching doesn't bring up any results. Any information on these?
It's a PCB finish, called Immersion Silver, or IS for short.
Some other common types of finishes:
- Hot air-levelled solder (HASL) - Just your normal solder, levelled with hot air knives.
- Electroless Nickel Immersion Gold (ENIG) - Your typical matte gold.
- Galvanic Gold - Different type of gold finish, looks shiny and polished.
- Organic Solderability Preservative (OSP) - Looks like bare copper.