Does anyone know if it's possible to make the userlist
translucent/transparent? Or even to set its colors?

I tried various combinations of color and alpha and they don't have any

What I want is the names and images floating against the background. I
don't want that striped box under them.

Or if anyone can point me to a GDM theme that might use anything other
than a standard userlist/face browser graphic I'd be very grateful.

Is there a way to do this with the 'custom widgets' they talk about? Any