Interesting to see the subtle SMK sticker on the back. SMK were Diatec's OEM before they went out of business and Diatec swapped to Costar.
The regular black had green alps from what I've seen researching and there was one with white alps.
Green as in linear? The only green Z mount Alps switches I'm aware of are Alps complicated (linear with LED cutout) and XM clones (tactile and linear, the latter also having the LED cutout).
Sounds like there's yet more colour abuse to uncover!