You can change the appearance of the search bar to match your phone's theme through the Google Help Center : Open the on your phone.
: Switch between standard, dark mode, or a custom color. Transparency : Make the bar more or less see-through. Shape : Change the bar from a rectangle to rounded edges. Managing the Widget Google Search Bar Widget
If the search bar is missing or was accidentally removed, you can easily restore it: : Long-press any empty area on your home screen. Tap Widgets at the bottom of the screen. Scroll down to locate the Google app category. You can change the appearance of the search
Select the widget, then tap and hold it to drag it onto your home screen. iOS Devices (iPhone/iPad) : Shape : Change the bar from a rectangle to rounded edges
Tap your or initial in the top-right corner. Go to Settings > Customize Search widget . Adjust the following: Shortcuts : Choose what appears on the bar.