Cupertinians return different customization options and changes in the appearance of macOS. Users can choose a static or dynamic desktop picture, but it is not possible to change the appearance of the boot screen.
The system will always default wallpaper from the installed version of macOS. But we see the screen of loading, locking or changing the user more often than the desktop of the computer.
It is often remembered how to change the background image of the loading screen that has bothered for a long time.
📌 Thank you restore for useful information. 👌
How to change the background image of the macOS boot screen
1. On the menu bar Seeker select item Go – Go to folder.
2. In the window that opens, enter the path: /Library/Caches/Desktop Images and press the button Input.
3. At the specified path, it will find a folder with a name of numbers and letters (this is the UUID of your macOS user), and in it the file lockscreen.png.
4. Copy the file to any folder on your computer, such as the folder Downloads.
5. Accessing file properties via context menu or keyboard shortcut team + me. In chapter More display the exact resolution of the image.
6. The playback you want to use instead of the default. It must have the same resolution, name and format *.png.
You can change the size of the image texture in any graphic editor or on the iloveimg.com website, you can change the file extension using standard macOS tools.
7. Replace the standard image in a previously opened folder with a new file lockscreen.png and restart your Mac.
8. If you want the wallpaper to change to the lock/user choice screen, you can easily set the same picture as your desktop background image.
For this revolution System Settings – Wallpaper and drag the image to the preview window.
Now you know how to replace the background image not only on the desktop, but also in any macOS system window.
Source: Iphones RU

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