I would say it's more on the warm side, for the retro biege that I have on hand. I believe the clean white would fit WS1 more, but I've attached some images of it with Minimal and DMG in different lighting settings.
Most likely clean white, though I have not seen NP PBT in person. Bear in mind that I also don't have the keycap on hand and can only refer to renders. The height will not match either.