This has happened in most of the apps in smartphones while Apple’s Mac OS was also given the option of dark mode a few years ago.
But now Microsoft has also introduced the Dark Mode feature for the Windows 10 operating system to improve the battery life of laptops and save them from the stress of working longer hours.
You can use Dark Mode as the default look in the Windows 10 operating system as well as in many Windows apps, however it is not possible to change the black color of some older Windows apps like Task Manager.
If you want to use Dark Mode in Windows 10 and its apps, here’s how.
To do this, go to the Start menu and open Settings.
Go to the Personalization option there and click on the Colors option on the left.

There, remove the default Windows mode and the default app mode from light to dark.

If the dark theme in Windows 10 settings does not apply to any app, you may need to go to the app’s preferences to do so.
For example, in the Mail app, click the Settings option at the bottom left and then Personalization, or in the New Edge browser, click Settings and then Appearance in the three dot menu on the right.
There you can adapt the Windows default theme from the app preferences, such as the Use My Windows mode in the Mail app and the System default option in the Edge browser.