Black background in Viewer Pane

I have a grey tone set as background colour in the Viewer pane.

a) If the viewer starts with a 'layout', it is black
b) If I select a large image file, the pane again shows black until the file is 'read'.
c) If I select a file that the viewer cant read, the pane stays black

I'm wondering is this the norm? And if so, can it be changed anywhere?

Found it
Prefs > Display > Other Colours > Viewer Pane background

There are two background settings for the viewer in Preferences:

Viewer - Viewer Pane - Picture background color defines the color used for the border around images that don't fill the preview panel. (There's a similar setting for the standalone viewer window in the same place.)

Display - Images - Viewer Pane defines the image and/or color shown in the viewer pane if no file has been loaded into it yet.

Sounds like the second one has been set to black in your case.

thanks Leo - yes,
the second one was set to black.

It hadnt occurred to me that there might be two different settings there. I've set both to the same colour now.

Off-topic: coming from version 8, I'm not used to using the filter for preferences but I've started using it now - it's wonderful, makes using prefs a whole lot easier.

This feature should be bog standard in all software... Is it unique to Opus...?

The Eclipse IDE has a prefs filter as well. Not sure if that's where the idea to put it in Opus came from or if it came from somewhere else.