Iqoo incoming call interface

If you plan to change the call background, you can go to Settings-Applications and Permissions-System Application Settings-Phone-Call Background-Call Background of Contacts/Call Background of Strange Numbers-Select.

Note: When "light color/dark color" is selected, the call background is desktop wallpaper. If you need to customize, just change the desktop wallpaper.

Other systems:

Call background displays desktop wallpaper by default. If you need to change it, just change the desktop wallpaper.