Go to File > Options to access the Outlook Options window.Here is how to do it in Outlook 2019 (including Outlook for Microsoft 365), 2016, 2013, 2010, and 2007. Apart from the default font for messages, calendar, etc., you can change the background color. Starting from Microsoft Outlook 2007, you can change Outlook’s appearance. Note: If Quick Repair does not fix this issue, you can try running the Online Repair as outlined above.: Some versions of Outlook allow you to turn on dark mode – which changes not only background colors of your Outlook, but also the body of emails.After the repair is finished, please restart the PC try the sync again.Select Online Repair and Continue then follow the prompts.(Selection also say Microsoft Office 365). WARNING: An Online Repair does an uninstall then a reinstall of Office, if something goes wrong in this process, you may need to reinstall Office manually which may require a product key Click Install and follow any prompts provided by the repair tool.

Select the Reinstall or Repair button, click Next.

Open Control Panel (Start>Settings>Control Panel).

Click Continue, and then Start Diagnostics.

On the Help menu, click Office Diagnostics.

After the repair is finished, please try the sync again.

Select Repair, Quick Repair and Continue then follow the prompts.

Click Change (may be listed as Modify).

(Selection also say Microsoft Office 365 or Microsoft 365).

Open up the Control Panel on your PC (and show All Control Panel items, if necessary) and click on Programs, then Programs and Features.

Outlook express 2019