Add or remove a sheet background - Microsoft Support
In Microsoft Excel, you can use a picture as a sheet background for display purposes only. A sheet background is not printed, and it is not retained in an individual worksheet or in an item that you save as a Web page.
Add or change the background color of cells - Microsoft Support
You can highlight data in cells by using Fill Color to add or change the background color or pattern of cells. Here's how: Select the cells you want to highlight.
Change the look and feel of Microsoft 365 - Microsoft Support
To change the color of your Microsoft 365 apps: Open a Microsoft 365 application, like Word, Excel, or PowerPoint. In the top left, select File > Options > General > Office Theme. Choose your favorite option. The default theme setting for Microsoft 365 is Use system setting, which matches your selected look in Windows.
Change the appearance of your worksheet - Microsoft Support
To change the text fonts, colors, or general look of objects in all worksheets of your workbook quickly, try switching to another theme or customizing a theme to meet your needs. If you like a specific theme, you can make it the default for all new workbooks.
Add a watermark in Excel - Microsoft Support
Create a watermark. Select Insert > Header & Footer. Tap on the header and on the Header & Footer Elements tab on the ribbon, click Picture. Select one of the available options to insert your image. In the header, you’ll see & [Picture]. Tap anywhere …
Refresh an external data connection in Excel - Microsoft Support
Block or unblock external content in Office documents. You can connect your Excel workbook to an external data source, such as a SQL Server database, an OLAP cube, or even another Excel workbook. This connection can appear in your workbook as a …
Use conditional formatting to highlight information in Excel
You can apply conditional formatting to a range of cells (either a selection or a named range), an Excel table, and in Excel for Windows, even a PivotTable report.
Change a theme and make it the default in Word or Excel
Insert subscript or superscript text in Word. Add or remove a sheet background in Excel. Create your own theme in PowerPoint. Customize or create a new theme with colors, fonts, or effects and save it for reuse, or make it the default.
Apply shading to alternate rows or columns in a worksheet
There are two ways to apply shading to alternate rows or columns —you can apply the shading by using a simple conditional formatting formula, or, you can apply a predefined Excel table style to your data.
Show or hide gridlines on a worksheet - Microsoft Support
You can either show or hide gridlines on a worksheet in Excel for the web. On the View tab, in the Show group, select the Gridlines check box to show gridlines, or clear the check box to hide them.