Hunting Default Preferences

[Jerry Jensen]

Hi folks,

I am returning to LiveCode after a spell of other projects, including debugging others’ LC code.

I find myself with a predicament - on launch of LC (no stack, just the LC app) I get a backdrop of off-white when I need none.
I have no idea how this got changed (never underestimate fatfingers).
There is probably a preference file somewhere that will let me change it back to the way it was (none) but I can’t seem to find it. 
I have looked everywhere that seems reasonable, but that is clearly not enough.

Its easy enough to put:
set the backdrop to none
in each mainstack opencard handler, but that is annoying at best.

Where should I look?

Regards,
Jerry Jensen
M1 MacBook Pro, OS 13.3.1 LC 9.6.9