Installing plasma-desktop package permanently changed Cinnamon theme to light

[WL72bFR5iD]

I'm on Linux Mint 20.1, Cinnamon. I installed KDE Plasma with the `plasma-desktop` package to give it a try. When I went back to Cinnamon, my theme became permanently stuck on a light theme completely different from what the theme should actually look like.

My theme is Baebae-gtk - note that it's a dark blueish theme from the screenshots.

After installing KDE Plasma, this is how the theme looks on Cinnamon.

I reset dconf settings, changed qt5ct settings, and tried everything I can think of with no luck. I created a new user account, which displays the theme correctly, and copied over the config files, but even that didn't change anything. I don't understand at all how the theme colors are changed, I even tried completely deleting and reinstalling the theme with no luck. Any ideas what's wrong?! I'd prefer not to have to migrate to a new user account just to fix this one issue.

[Moonstone Man]

I'd prefer not to have to migrate to a new user account just to fix this one issue.

You're going to have to do far more than that, either restore from a timeshift snapshot, revert to a restored clonezilla image or similar, or clean install.

When you create frankenstein desktops as you have done, there's no telling what other inconsistencies exist. One of the major problems is plasma services starting up while trying to run another DE. We see posts like yours regularly, and I'm afraid that I have to tell you that since you made the mess, you get to clean it up.

[WL72bFR5iD]

Thanks for your reply. I reverted to a Timeshift snapshot I made earlier in the day before installing plasma and the issue persists. I'll try going back farther.

[Moonstone Man]

Thanks for your reply. I reverted to a Timeshift snapshot I made earlier in the day before installing plasma and the issue persists. I'll try going back farther.

If the timeshift snapshot was dated before the installation of plasma then some file in your personal settings under /home has been corrupted. Going back further in timeshift won't fix it.

[Hoser Rob]

This is just one reason why you shouldn't install multiple DEs. I can't beleve how many so called 'experts' on Linux forums say it's OK. I've even seen forum moderators do this. Unfortuinately the best/easiest/quickest fix for these problems is usually a clean reinstall.

[WL72bFR5iD]

I managed to fix it! In ~/.config/gtk-3.0 there was a colors.css file and gtk.css file. These must have been overriding my GTK theme colors since they defined variables that I noticed overlapped with the theme variable names. After removing these two files, the theme looks as intended.

Thanks for the warning about multiple DEs, I'll be more careful in the future. I've learned my lesson and understand this may not be repairable next time without a clean install.