The Gboard keyboard on the Oppo smartphone doesn't offer a lot of customization options in terms of design. Gboard allows you to change color combinations or set gradients and backgrounds, and you can also use your own backgrounds such as photos for the keyboard.

Android 10 | ColorOS 7.0
Step 1:  Open the  Settings
Step 2:  Tap on  Additional settings
Step 3:  Tap on  Keyboard & input method
Step 4:  Tap on  Gboard
Step 5:  Tap on  Theme
Step 6:  Choose desired  Theme
Step 7:  Confirm with  Apply
  1. Open the Settings
  2. Tap on Additional settings
  3. Tap on Keyboard & input method
  4. Tap on Gboard
  5. Tap on Theme
  6. Choose desired Theme
  7. Confirm with Apply

Oppo Instructions