Question about Model F XT PCB

[OldIsNew]

I saw a pic of a Model F XT PCB on eBay that looked unusual to me. The contacts and tracings appear to have a black coating similar to a 3276 beamspring PCB I saw on the Wiki here. Has anyone seen F XT PCBs like this? Any significance to it?

F XT PCBs I've seen

F_XT_PCB.jpg (66.89 KiB) Viewed 901 times

The F XT PCB in question

xpcb.jpg (205.14 KiB) Viewed 901 times

3276 beamspring PCB

800px-PadCardFront.jpg (77.49 KiB) Viewed 901 times

[Engicoder]

There are several different versions of the XT pcb. The top image in your post with the gold colored pads and traces are the most recent versions. The second picture with the dark pads is one of the earlier versions. You can also notice that the pads on the earlier version have rounded corners unlike the later versions which have sharp corners. The later versions are marked "Made in Hong Kong" while the earlier versions have not origin markings. I assume that the difference PCBs were manufactured by difference facilities. I believe the dark color of the pads and traces is due to differences in manufacturing the composition of the solder mask used.
There is also a very early version of the PCB which has more copper colored than the two pictured here.

[OldIsNew]

... The second picture with the dark pads is one of the earlier versions ...

I was wondering if it might be something like that. Thanks for all the info!