I have a Midnight Blue Precision from the late '90s.
It came with a white pick guard.
I was tempted for the longest time to change it to black, which DOES look really good, but really now the original white has aged to the point it is just started to get a slight yellow/gold tint it just looks too perfect to even mess with. Nothing like the mojo of an aging bass.
This is an older picture, I need a more up to date one but regardless I'm sure my cheap cellphone camera wouldn't pick up the nuances of the slight color change I was talking about.
So sheesh......what I guess I'm saying is, either white or black would work well IMO.
Oh, I'm sure if you're even remotely skilled with a drill and reamer and such it would be no problem to drill another hole for the extra knob. Someone much more experienced than me will have to say whether the standard pick guard would fit though.