P. Phillips wrote:
The Wallpaper that appears at the Log In page where the use has to manually input the Computer Password can be changed and Only provide the two conditions are met.
1 - There is Only 1 User account on this computer. Not even a Guest Account is permitted.
2 - FileVault must Not be enabled on this computer
For detailed instruction suggest following this very good illustration from @jefferythefrog
https://discussions.apple.com/thread/253382773
actually, the single user account AND fike vault being disabled is still a requirement, but the settings options screen is slightly different as of Ventura.
if you are the sole user (not even a guest account) AND file vault is turned off you can go to System Settings, in the Lock Screen tab, and set "Login window shows" to "List of users". then your login screen matches your desktop background.
but as before, if you are using file vault or have multiple users, the above will not work. if that's your situation, you will need to wait for apple to address this. it may be worth your time to send feedback directly to apple. Feedback - macOS - Apple