Microsoft Word, Microsoft Excel, and Microsoft PowerPoint allow saving the background color or image to HTML.
Excel supports the saving of a background bitmap through the background attribute of the Body element. If all cells are selected and a background color for cells is chosen, the background color is defined through an HTML class setting that is used by the table that defines the cells.
PowerPoint saves slides to a Web page frame. The frame color can be specified for multiple slides. The background of a slide is specified by the master slide, which can store colors using the standard HTML background-color style attribute of the VML Shape object used to create the slide. Image fills created by themes can be stored as bitmaps or as VML shapes stored in a master XML file.