Formatting the report background
In the Format Background dialog box, you can apply a background color, image, or color and image, to all cells in the spreadsheet.
You can use the Format Cells dialog box to apply a background color to one or more cells, but not to all cells.
See Formatting cells.
You can insert an image into an individual cell, but not to all cells.
See Inserting images.
To format the background of all cells in the spreadsheet with a background color, an image, or both: