Yes, I was about to say they came with white but I've a feeling they may have been tort, unless I toyed with the idea of tort, I know the P had tort at some point, anyway rambling. I just bought the black ones from ebay, el cheapo, no name jobbies and they fit handsomely. It's possible a couple of screw hole might not have lined up perfectly, I can't remember, but as they are cheap basses a couple of fresh holes wouldn't have hurt.
I don't know when they started making the STB series but the P has some wonderful aged colour to the neck. A real vintage darkening that isn't a stain. The J is much lighter.
I actually gigged the P for about a year when I got it as it just feels so nice. With that band I always went through the PA with a monitor so I plugged in via a Behringer BDI21, forty pound bass, 30 pound pedal, I'm done 😁. Such a liberating way to gig.