Hi,
i want to add background image (i choose black image for all standard image). it's ok for :
- folder tree
- contacts list
- statusbar
- folder tabs
but what's about file display and viewer pane ?
The viewer pane only displays a background image when it isn't showing anything else. (Open it when no files are selected to see.)
The file display background may be obscured if Prefs - Display - Optons: Blend file background colors with background is turned off. Is that it?
it's ok
No background when "Blend file background colors with background" is turned on or off. 
What's configured for the background if you open Tools -> Folder Options and go to the Options tab? Maybe the folder format overrides the background image or colour.
if i choose "defaut image" nothing, i need to select "standard file display image" to show background.