OS: Windows 7 - 64bit
When creating a contact sheet the preview uses a black backcolour. It's unclear where and how the user can set this background colour.
Effect: Irritating user interface.
To reproduce:
1. In XnView browser select multiple image files.
2. Select Create » Contact sheet
3. In dialog "Create contact sheet" check "Footer" and enter some text.
4. Switch to "Preview" tab.
Actual behaviour (bug): Preview tab is displayed. The preview is shown with a black background.

Expected behaviour: The preview should be shown with a standard background colour which can be set in XnView. E.g. the background colour of the "Preview" could be used.
Note:
The preview in "Print" dialog also has a different background colour.
Note: When checking "Header" and the preview is updated and contains both header and footer. Looks like setting footer doesn't trigger an update of the preview.