Solution for changing Big Sur login wallpaper to custom.

Not sure if this is where you're stuck, but it's what finally fixed it for me: in System Preferences > Security & Privacy > FileVault, it's turned on by default and you'll see the "Turn Off FileVault..." button grayed out so you'll have to click on the lock icon in the lower left corner and enter your password to change the setting. The button will then be enabled; follow the prompts to turn off encryption and you're done.

I hope this helps!

here are the screen shots

Hi Soren

I was not looking at the right directory, I switched to the entire Mac drive the UUID world was already there

but does not contain the grotesque Big Sur lock screen image.

I created a new UUID and renamed it again placed a new image in put it still comes up with the ugly Lock Screen image

I have two Desktop Pictures folders with same UUID,

This method does not work on the latest version of Big Sur 11.0.1

Why are we not allowed to change that rainbow colored login/switch user/lock screen ?

I have followed all of your steps and it still did not work. Even after both a restart and shutdown.

Any workarounds that you know of ? I have 2 user accounts and always leave the log-in screen up so this rainbow color background is incredibly annoying for me.

The startup screen on my iMac looks like this:

But, of course, with my name and image and a second "Guest" image before it advances to the login screen where I can type my password. I would VERY MUCH like to change this, initial screen so that it matches my login screen.

Daniel

This screen will always have the Big Sur Graphic image («the rainbow colored background»).

We have not found a way to change this image, or the image used for this Login Screen («log in screen» or User Selection Screen).

I used to bypass the Windows10 screen using

https://www.thewindowsclub.com/ultimate-windows-tweaker-4-windows-10

I was hoping Onyx could do the same.

We'll keep our detective hats on for this one.

Somebody's gonna solve this mystery. . . eventually. . .hopefully. lol

Thanks for your swift responses. I really appreciate that.

Marked as helpful.👍

HippieFlowers,

I assume you entered your admin password to unlock permissions for Users & Groups and that your account is an Admin?

If you right click your user name under Current user list you should see this.

Hope this helps.

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.

I took the approach of visiting the Users & Groups Preferences panel, and altering the Login Options to Display login window as: ⦿ List of Users. A logout or log-in now shows my chosen Desktop wallpaper with my avatar above my name and password window. Gone is the ghastly bright Apple genuine migraine wallpaper.

The avatar window does not support transparency, but it might get a dark background shortly.

As VikingOSX said, change to 'list of users' rather than trying to change the Big Sur boot up image.

My system has never had a different 'log in' and desktop. Whenever I've right clicked on an image and selected 'set desktop wallpaper', it's always changed both.

However, the boot up one has always been whatever Apple set it to when changing the OS.

If your log in options are changed to 'list of users' as stated, the boot up image will be whatever your wallpaper is.

My guest user is always turned off, so if you have this on, you might need to turn it off—I'm not sure.

A kelp forest isn't a field of "distracting details." The fronds lend themselves to an impressionistic representation that would make a nice login screen, e.g., from this image (from the Farallon islands, just north of Monterrey)

Thanks!

If I may, I want to point out to others (who, like me, may have failed at this so many times already after reading many online posts about this) that the place to find the Desktop Pictures folder (or to create that folder if there is none there) is inside your boot drive's Library/Caches folder... not inside the user/[username]/Library/Caches folder. In my case I had to create a Desktop Pictures folder and, inside that folder, create my UUID folder.

Applewarm's steps (where you change the desktop image as the last step before restarting) is the way to do it. But, I noticed that if you want to add a custom image to the UUID folder, so that the lockscreen image is your custom image, different from the desktop image, you need to define your desktop image first, via system preferences, restart the computer, then replace the lockscreen.png image in the UUID folder (which, if you look at it will be an identical image to the desktop you defined before restarting) with your custom image. Looks to me like whenever you change your desktop image via sys prefs and restart, the lockscreen image in the UUID folder gets replaced with the same image as your new desktop image (wiping out your custom image there).

I think.

Anyway... thanks applewarm.

This procdeure changes litteraly only the "login" screen, isn't? I mean, you still have the big sur wallpaper every time you switch on the machine, right? (For login screen i mean the one you see when you logout from your account)