Довідка LibreOffice 6.1
Specifies the background for HTML documents. The background is valid for both new HTML documents and for those that you load, as long as these have not defined their own background.
Further information
Щоб скористатися цією командою…
Відкрийте HTML-документ, виберіть LibreOffice - ПараметриЗасоби - Параметри - LibreOffice Writer/Web - Тло.