Heavy - of course not. Does anyone really want to lug a lump around the stage?
Colour - really not a fan of pastel shades. Sky blue or sea foam green? Nope.
Strings - four. Anything else is like playing an ironing board. I suspect that may just be my lack of talent.
Pickguard - Nope. You can have natural wood, sparkle or three tone sunburst and then screw on a lump of plastic. Really? If you have to have one it has to be as inconspicuous as possible. Tort is almost acceptable.
Pickups - single coils, thank you very much!
Headstock - not really a prejudice but my first ever bass was a 4-in-line EVERYTHING I’ve ever bought since is 2+2. Don’t know why!
Electronics - passive. Don’t want another point of failure.
Having said all that, I do have basses which weigh too much, have pickguards, have active electronics and/or humbuckers.
Bottom line is that everything is negotiable… except Shell Pink!
Maybe…