How did the screen wallpaper color of vivo mobile phone change?

According to your description, it may be that the color inversion function of the mobile phone is turned on. You can enter Settings-Quick Assist/More Settings-Assist Function/Assist Function-Color Reversal to close.

Note: If there is no auxiliary function or color reversal switch, please refer to the following methods:

Download UC browser, and then enter the UC browser interface-click the menu at the bottom of the screen-gear icon in the lower left corner-advanced settings-turn on the automatic installation application switch-turn off the color inversion switch.

Still unable to recover, it is recommended to take your mobile phone to the service center for testing, enter the browser to search for vivo official website-service-service center-view all-select provinces and cities to query the address and contact information of local service centers.