Joke Collection Website - Blessing messages - How does opp oR9 set the call background picture and SMS picture?

How does opp oR9 set the call background picture and SMS picture?

1, the contact number is saved in the mobile phone, and the wallpaper can be displayed during the call. This is for a single contact. If you want to replace them all, you can download third-party application themes for use.

2, the latest ColorOS version, change the desktop wallpaper, you can modify the call background picture.