Hello, the black background of Huawei mobile phones means that the "dark mode" is turned on. The function of this mode is to save power and protect your eyes. The switching method of turning it off and on is as follows:

1. First open your Huawei phone and click the "Settings" icon on the desktop.

2. After entering the Huawei mobile phone settings interface, find "Display and Brightness" and click to open it.

3. After entering the interface, click the "switch" to the right of "Dark Mode" to switch and turn off the dark mode.

4. As shown below, after entering dark mode, it will change to white text on a black background.