Why is the font white?

First look at whether the brightness of the mobile phone is too high and whether the white point value is turned on (this is the most likely).

The stupidest thing to do is to restart (power off and power on) or redo the annual setting.

Second, there may be something wrong with the mobile phone software. Please try to delete it and download the software again.

Third, there may be something wrong with the system. See if your mobile phone needs software update.

Fourth, if all the above methods fail, please connect the computer with USB cable, and then manage the mobile phone with some applications (this is a bit difficult for you).

If all else fails, you'd better make do with it first, because in this case, you'd better not leave home.