The update for Android Oreo removed the native functionality that allowed the user of various Xperia devices to customize the interface in different ways, which went a bit beyond wallpaper, icons and appearance of the home screen, always quickly and easily.
The Xperia XZ2 hit the market with a new system that reopens all these possibilities, even with Android Oreo already installed. And to the joy of Sony users, developer niaboc79 has published in the XDA Developers forum a way to re-enable these functions on older devices such as XZ, XZs, X Performance, X, XZ Premium and XZ1.
Step by step varies depending on the device. But the instructions are all on this topic from the developer’s forum. Interestingly, the two smartphones that seem to have the most complicated process are the latest, XZ Premium and XZ1.
https://youtu.be/s__3eD22Oy4
Only for these two is the recommendation to make a backup, but it does not cost anything to copy your files regardless of the devices you use. There is no need to root on any smartphone for the new theme system to work.
If you are thinking of switching smartphones and think this might be a good sign to start looking for a new device, take a look at our previews of the Xperia XZ2. We have also published the review of the XZ2 Compact, which has some minor differences to the larger model, only.
Source: XDA-Developers