Android
Set Dark or Light Theme for the Phone App auf Android
The Phone app on Android often keeps its own theme setting, separate from the system-wide light or dark mode you picked elsewhere. That is why calls, the dialer, and the recent calls list can stay bright even after the rest of your phone switched to dark.
Google ties this option to the visual comfort of the dialer and call screens, not to battery saver or automatic system theme sync. Dark theme lowers screen brightness on OLED panels during calls, which can slightly extend battery life and cut glare in low light.
Menu path to change it
Open Phone ➔ Open the Menu ➔ Tap on Settings ➔ Tap on Display options ➔ Tap on Choose theme ➔ Select Light, Dark or System default.
Picking System default links the Phone app back to your Android theme setting, so it switches automatically with the rest of the interface. Choosing Light or Dark manually overrides that link and stays fixed regardless of what the system does.
If the option is missing entirely, check for a pending update to the Phone app itself. Older builds, especially on Android 12, sometimes only offer the system default toggle without independent Light or Dark control.