For easy searching, “WOB” and “BOW” are often used for the white legends on black keycaps, and black legends on white keycaps. Even MOA, which started with almost exclusively very “kawaii” sets can now be had with even more staid designs than yours, though the only BOW set I found still makes you use a novelty Enter key, or else one that’s color-inverted and has the wrong font. The spacebar is also black.
We do love our pretty colors, though. I’m currently typing this on my GE Medical Model M, which is mostly gray, but with all the unusual legends and sublegends for the medical device it was originally used for. F12 is red (and called “Emerg Save”), and the numpad is 75% yellow with not a single “accurate” legend at all. And that’s one of my vintage boards, LOL, although it is the most exotic looking of those.