Hello. Does anybody know how whether the keyboard that appears when adding a source to installer.app (and also a few other times throughout the OS) is a new design or whether it is just a transparency or effect of some sort (like when a message pops-up and the corners vignette)? - I ask this becuase that black keyboard looks amazing in comparoson to the original.

I understand that you can modify the keyboard yourself - but this seems quite complex, also the ones that are available from others just don't cut the mustard in my opinion.