Please, keep apps is same original design! And move all apps data to ~/snap!

Example some apps in snapcraft store:

it is really hard to decipher what you want to tell us, could you elaborate ?

I meant: “the color of some buttons/layouts looks like the background color of the app” and “location of data/cache should be save in to $HOME/snap”

ah, this is commonly called themeing … (and it sounds like there is a bug to be fixed)

while snaps save their data in $HOME/snap/{current|common}, non snapped apps and your desktop do not … and for some bits (i.e. your font cache) there have to be some shared system bits in hidden directories like ~/.cache or ~/.config, this is sadly not avoidable… (but these dirs are normally not visible in default filemanager setups)

ah, when i re-install OS(kubuntu), i re-imported $HOME(/home/username) and i change ‘chmod -R 764’ and ‘chown -R username: /path’ inside $HOME folder, now libreoffice look like this:

but three buttons - [] X on firefox browser when active light theme look is very bad =((

to back up your data you should take a look at snap help save and snap help restore

the snapshots get stored in /var/lib/snapd/snapshots/ as zip files that you can copy to some USB drive or temporary store in your home dir …

then after re-install you install back all the snaps you had in snap list on the old system, copy the zips back to /var/lib/snapd/snapshots/ and restore them.

this is way cleaner and should not cause breakage like you see …