Can you try like this:
sudo KDE_SESSION_VERSION=6 snapper-tools
Or like this:
sudo XDG_CONFIG_DIRS=~/.config/kdedefaults snapper-tools
^^no go.
This works:
sudo -E snapper-tools
^^^ not on mine, but I use KDE Lite.
That looks good! Is that the right theme? It looks the same as Btrfs Assistant?
Oh thatās interestingā¦but sudo -E works?! So there must be something else in your user environment that is providing the theme. 
Yes it themes correctly with sudo -E
Yes, I am on dragon KDE 
ive been using KDEās iso tool its simple an to the point. Arch Linux - isoimagewriter 24.12.1-1 (x86_64)
I used to use fedoras but its a bit slow on start and I started testing banana os a while back.
*Note Iām using a gray theme.
Also on windows.
People seemingly like it 
but yes we donāt need to argue about this being a non-bloated app haha.
@BluishHumility This desktop file using sudo -E works to start btrfs-assistant` via a desktop file:
[Desktop Entry]
Categories=System
Comment[en_CA]=Change system settings
Comment=Change system settings
Exec=/usr/bin/sudo -E /usr/bin/btrfs-assistant
GenericName[en_CA]=
GenericName=Btrfs Assistant
Icon=btrfs-assistant
MimeType=
Name[en_CA]=Btrfs Assistant
Name=Btrfs Assistant
NoDisplay=false
Path=
StartupNotify=true
Terminal=false
TerminalOptions=
Type=Application
X-KDE-SubstituteUID=true
X-KDE-Username=
I know you hate using sudo -E because of itās security implications, but for some off the Garuda utilities itās the only way the desktop launcher to start with proper theming. At least for me on the barebones/Lite editions.
I didnāt have that exact issueā¦ but (kind of) continuing from this, some of the buttons are hard to see during the installation because of the font colour when they are not focused (or when they are focusedā¦ sorry, bad memory ^^;).
It seems to affect these points in Calamares mainly.
Other than these, using it on bare metal and it looks good! I fixed the awkward clock by making the font smaller instead, and also increased the left and right padding of the top bar so the icons arenāt touching the sides of the screen for the translucent bar.
Great work Garuda team!
Idk how long I will use this before I delete it though, because Iām too used to the WMs now 
This would required patching Calamares and rebuilding it. We will see what to do.
I launched Snapper from the terminal on the test release:
āāarclite@gt70 in ~
ā°āĪ» /usr/lib/garuda/pkexec-gui snapper-tools
"8d005eb6-2640-4cef-91f7-2fa30e98044b"
"Mounting 8d005eb6-2640-4cef-91f7-2fa30e98044b"
fish: Job 1, '/usr/lib/garuda/pkexec-gui snapā¦' terminated by signal SIGSEGV (Address boundary error)
āāarclite@gt70 in ~ took 17s
[ā”] Ć
The gui window that popped up just closed when I pressed the āsettingsā button. The same also happens when I launch Snappper from the menu. I went to the current release, where the gui just closes when clicking the āsettingsā button. All systems updated 2/4/24. No dual booting. All on real hardware. BTW the gui opened correctly.
I donāt hate sudo -E, it is useful for troubleshooting. If you want to run applications like that on your own system, thatās one thing but obviously we canāt put sudo -E in the actual desktop file for the application that we provide to users.
On itās own, the fact that the theme works correctly with sudo -E doesnāt tell us much except that the theme needs something in the user environment. Instead of passing the entire user environment to root with sudo -E, if we can figure out what specifically is needed then maybe we could add that to the pkexec tool or add it directly to the desktop file with a env parameter.
Maybe there are better ways to do this, but one thing I have done to isolate a needed environment variable like this is list them all out in a space- delimeted line like this:
env | tr '\n' ' '
Then copy and paste that whole string of environment variables in between sudo and the command you are running:
sudo SOME_VARIABLE=some_string ANOTHER_VARIABLE=another_string AND_SO_ON=and_so_on [...] snapper-tools
This should have the same effect as running the command with sudo -E (adding that whole lengthy list of environment variables to the command is essentially what sudo -E is doing).
Then, delete ten or so of the variables from the command and test again, and see if the theme still works. If it does, delete another ten, and so on until the theme breaks. Once the theme breaks, you know one of the ten variables you just deleted is what preserves the theme. From there you can narrow it down to one or a few environment variables.
If we can identify a needed environment variable, maybe we can add it to the desktop file or to the pkexec tool.
ā¦ now i tried all tools mentioned here to create a bootable usb-stick (garuda-dr460nized-linux-zen-250204.iso); on all the same error;
but when i use the latest official iso (garuda-dr460nized-linux-zen-240428.iso) it works >>> any ideas ???
This is already known:
This new test iso also worked for me.i got same results like you.
https://iso.builds.garudalinux.org/iso/garuda/dr460nized-gaming/250131/
Thanks Nepti for linking. 
The āsettingsā button in snapper-tools hasnāt worked for almost a year:
Current as of today:
Feb 04 16:59:44 archangel kernel: snapper-tools[21551]: segfault at 653800000004 ip 000072cece578dbd sp 00007ffc66ac83f0 error 4 in libQt5Core.so.5.15.16[178dbd,72cece497000+2fe000] likely onCPU 2 (core 2, socket 0)
yeah thats true.
I also use Timeshift as Snapper tool. Its in conflict with Snapper-Support ive deleted and use Timeshift there i can use Settings . Maybe an idea for new release to use Timeshift=)