Solution for changing Big Sur login wallpaper to custom.

I did not have fire vault turned on,

I stumbled upon this and it worked for me.

I had a two other accounts on my mac

A guest user and a TEST account.

I went to System Preferences, Users and groups. ( unlock your padlock to do this)

and Deleted my TEST User account completely.

You can't delete the Guest account but you can turn it off here (

then goto the Apple icon (upper right) and select "Lock Screen"

my user log in screen was there so I chose it.

it worked for me.

James

Halliday,

I assume you mean OnyX?

It looks like OnyX has been released for MacOS Big Sur and from downloading it and looking, it has the option under Parameters > Login to change the background image.

I don't know if it works with a multi users setup or File Vault as I haven't tested it as I was able to follow the steps above. For those that want to try, please report back how it goes especially with a multi user set up or File Vault enabled or both.

Hope this helps.

IvE46,

Do you have a multi user set up or have file vault enabled?

So your saying that the lockscreen.png file is correct but the login wall paper doesn't show correctly?

I would give OnyX a try and see if that allows you to change your login wallpaper.

Hope this helps.

I did change my desktop picture from the rainbow to the coastline. that's the first thing I did after installing.

I created the folder in the right directory and was then able to change the login background.

The welcome login screen is still unchanged, does anybody really have a working solution to this annoying bug? Just to reiterate I'm not talkinmg about the screen background once you've logged in thats easy as pie, I mean the welcome login screen say once you restart the mac/ reboot etc.

I hadn’t noticed any change in the Lock Screen for my usual user account, woodmeister50, but I just checked my wife’s account, and found it’s Lock Screen had reverted back to the Big Sur Graphic image.

Logging into her account, finding that her Background was still as usual. I reset her Background to be her choice, and logged out.

After that, her Lock Screen is now like here Background, again.

Is your system a Single-User system, or Multi-User?

Thanks for the info!

Unfortunately, that's what I already saw online and what I did - a couple times - unsuccessfully. The lockscreen.png image inside the Library/Caches/Desktop Pictures is NOT the ugly, multicolored lockscreen image that appears when I start my iMac, but I replaced it anyway with a new image named "lockscreen.png", renaming the old image to "old-lockscreen.png" and leaving it in the UUID folder in the Desktop Pictures folder. Restarting did nothing in terms of changing the lockscreen image - it's still that horrid, multicolored monstrosity (or maybe it's "art"? Maybe something Tim Cook painted in his spare time? ;) lol)

Anyway, thanks, again, for the info! I'll keep looking for a solution and hoping that Apple changes either the lockscreen, or adds an ability for users to change it, in the next update.

The solution works where you have one user defined on a mac. On a mac where two or more users are defined, it does not work at all. Any insights to resolve the annoying red/blue login background in a situation where you have two or more users configured to use the same mac? Possible for Apple to remove the Red/Blue login screen urgently OR give an option on the change without going through a "thousand" tech step?

Yup, that's what I ended up doing. I turned off the Guest user login and it worked fine. But, it would be great to have the multi-user login page configured with a background of the user's choosing.

I think you don't have the Desktop Pictures folder in there because you had not changed your desktop image yet.

You should be able to set up that wallpaper then delete the folder that has it. Turn back on FileVault then restart.

My wallpaper reverted to the original when a beta update for Big Sur came out.

Pantload,

I believe you asked same question earlier.

This does not work on a multiple user setup, only a single user.

Hope this helps.

Update. Once FILEVAULT is reactivated it goes back to the rainbow wallpaper. Bummer. New wallpaper is not worth the security risk.