Previously reserved for the users of launchers, the option to customize the Google Search bar widget has been a long time coming in the official Google app. Earlier this week, people running the latest beta version of the app began reporting that the feature was going live for them.
The Google widget is by default a plain, white rectangle, but with the new customization features added to the Google app, you can round its corners, or turn it into a Material pill shape. You can also choose between displaying a "Google" or a "G" logo in the bar, and tweak the color and transparency of the widget.
notes that the new customization option has been spotted on devices running the latest beta of the Google (version 8.21). However, earlier this week, there were reports the feature going live in the stable version of the app as well.