Oppo
Change Keyboard Theme (Gboard) auf Oppo
Gboard is the default keyboard on most Oppo phones running Coloros, and it keeps its design options separate from the main system settings. That is why the keyboard often looks unchanged even after you tweak the phone theme or wallpaper.
To open the correct menu, follow this path:
Settings ➔ Additional settings ➔ Keyboard & input method ➔ Gboard ➔ Theme ➔ Choose a Theme ➔ Turn On/Off Key borders and tap Apply
Inside Theme you can pick a preset color scheme, apply a gradient, or select a photo from your gallery as the keyboard background. Turning on Key borders adds a visible outline around each key, which helps with typing accuracy on busy or dark backgrounds. Turning it off gives a cleaner look but can make it harder to hit the right key on some custom images.
Custom photo backgrounds use more memory and can slightly affect keyboard load time on older devices. If typing feels delayed after applying a photo theme, switching back to a solid color or a lighter preset usually fixes it. This setting only changes Gboard. If you use a different keyboard app, its theme options are managed separately.