Though I don't recall seeing this color (pale yellow?) on black before. Hope JP will comment.

Though you did not attach a ruler, the beads look rather huge. 16-18 mm or so, as my left eye insists!

That, if true, together with the unusual colors, the somewhat different "design-chen" and the fact that you got even several of this (possibly rare" pieces make me scratch my head!

On the other hand - looking at and into the apertures, my right eyes is no longer sure what the other one signaled to my brain!

Authenticity factor:
40:60

Never saw the black with yellow yet, nice find, they look good to me and their size is pretty much average of the ones found in the African trade.
These "Zen" beads in the regular black and white come in diameter from ~ 6 to 20mm
JP