I think in the page style window, that's only for the open document, but you should be able to save that as a permanent default, you just have to do it the hard way. I found something else that tells you how to save settings as default. This is answering a question about margins, but I think you can start at step 4.
http://wiki.services.openoffice.org/wik ... _1_inch%3FFirst, set up your page how you want it to always open, then:
4. Choose File > Templates > Save Under Categories, select My Templates.
5. In the blank space under the words New Template, type a name for your template.
6. Click OK to close the dialog box.
Then, set your new template as the default template:
1. Choose File > Templates > Organize. Double-click My Templates
2. Right-click on the new template name that you selected in step 4.
3. Select Set as Default Template.
4. Click Close to complete. Close your template file.
Hopefully now it will always be black background with white text whenever you open LibreOffice.
And for printing options: If you print it with a black background, that would use a lot of ink! And the paper would be wet and would weigh a lot too. But it's your ink, your choice
