The dark mode feature on the Search app supports system-wide dark mode and so it by default adopts the smartphones default theme. If your smartphone does not have a system-wide dark mode feature, the app also gives the option to manually change the theme. You can even opt for the permanent dark theme as well.
Wondering how to enable dark mode in Google app, follow our step-by-step guide
Android 10 or above
iOS 12 or above
The latest version of Google app
Steps to enable dark mode in Google app