Can someone suggest why, every fortnight or so, I notice that my ColorSync
has vanished from my beige-box Macintosh G3 computer?

After it vanishes I need to restart from my OS9.1 CD and then reinstall it.

I notice the loss when I try to use my GraphicConverter (that program tells
me that the absence of ColorSync has prevented it from starting). Nowadays
my use of Photoshop or other graphics software is rare (and anyway I don't
know whether any of them needs ColorSync), so I'm unsure whether ColorSync
vanishes sooner than about a fortnight after I've reinstalled it.

In my wildest daydreams I imagine that my computer is harboring a bolshie
piece of non-Apple software that thinks it has the right to delete or
supplant my ColorSync. Is that likely? If it is, then what's the culprit?

I'll answer any question about the other software or hardware that my
computer uses.

Quentin Burward