Xiaomi
Dark or Light Theme for the Phone App auf Xiaomi
The Phone app on Xiaomi phones has its own display setting, independent from the general system theme. If you only change the overall MIUI theme, the dialer, call screen and contact list can still stay bright or dark on their own. This is why the app can look out of sync even after you switched Dark mode everywhere else.
Where the setting lives
The option sits inside the app itself, not in the general Display settings. Open the following path:
Tap on Phone ➔ Open the Menu ➔ Tap on Settings ➔ Tap on Display options ➔ Tap on Choose theme ➔ Choose Light,Darkor System default
Picking Light or Dark forces that look for calls, contacts and the dial pad regardless of the rest of the phone. Choosing System default links the app to whatever theme MIUI currently uses, including automatic day and night schedules if one is active.
Use a fixed Light or Dark choice if you want the dialer to stay unaffected by scheduled theme changes, for example to keep the call screen readable in bright sunlight. Use System default if you prefer one consistent look across every app without adjusting the Phone app again later.