So i installed minimal Manjaro and have installed Flatpaks and those wont respect my systems theme. I don’t even have the option for the theme for example in OBS.
Is there something i can do about it? I have tried searching for it in the internet, but i haven’t yet found anything that works.
I would start from the ArchWiki:
https://wiki.archlinux.org/title/Flatpak#Flatpak_applications_not_picking_up_the_default_system_theme
I already searched Arch wiki. It just recommends you to add overrides for .themes folder and .icons folder which both don’t even exist on Manjaro. Also the QT app guides don’t work.
The main problem remains in that Flatpak, like all so-called containerised applications/packages are by their very nature isolated from the system.
Whatever theme is defined within the package is generally what you get, unless the author has taken the time to include theming for every contingency.
When containerised apps are ‘installed’, a desktop file might be added to the menu to run it, but as far as other integration is concerned, that’s about the extent of it.
These are some of the tweaks that might be added. Perhaps the author of whatever Flatpak is concerned might be able to better explain things in relation to that package.
Beyond that… 
Regards.
[nx-74205:/dev/pts/3][/home/aragorn]
[aragorn] > for directory in .themes .icons ; do ls -l $directory; echo --- ; done
total 0
drwx------ 1 aragorn aragorn 42 Aug 8 2021 Carl
drwx------ 1 aragorn aragorn 168 Aug 26 2023 E17gtk
drwx------ 1 aragorn aragorn 176 Nov 10 2020 Gradient-black-325
drwx------ 1 aragorn aragorn 176 Apr 27 07:45 Kripton-standard-buttons-v40
---
total 0
drwx------ 1 aragorn aragorn 60 May 18 2024 'Night Diamond (Blue)'
drwx------ 1 aragorn aragorn 36 May 17 2024 WhiteSur-cursors
---
[nx-74205:/dev/pts/3][/home/aragorn]
[aragorn] >
You were saying? 
Flatpak documentation - Desktop Integration
Theming
Flatpak applications cannot directly use the system theme from the host as the
/usrdirectory inside the sandbox is reserved by the runtime, and host’s/usrwhere system themes are typically stored cannot be made available over that. Additionally, themes often depend on specific toolkit versions, which may differ between the host and the runtime. Relying on the host to have the correct version for every flatpak also defeats the portability benefits Flatpak provides.The solution to this is to package the themes as flatpaks. These themes are provided as Extensions to the Freedesktop runtime for Gtk3 themes and to the KDE runtime for Qt themes.
Icons
Since Flatpak 0.8.8, host icons from
/usr/share/iconsare exposed in the sandbox at/run/host/share/iconsand$XDG_DATA_HOME/iconsin/run/host/user-share/icons.
~/.iconsis a legacy path and should not be used.
That answer assumes that you do have your themes and icons in those directories - which is not the case when you use the themes and icons that come with the Manjaro installation.
These are in /usr/share/themes and /usr/share/icons.
In $HOME/.icons and $HOME/.themes you can put themes and icons that you don’t want to be available system wide, but just for this particular user.
… simply create these folders and put the themes / icons there
That is correct. This will be the same for many Linux distributions and it is not a flaw.
A skeleton home is provided in /etc/skel. Such skeleton does NOT contain each an every possible file an folder which may or may not exist in any given user’s home at any point in time.
If you see references to such folders - you simply create them and populate them with the necessary files and folders.
With regards to the minimal ISO, there is a reason it is labelled minimal.
The minimal system will always need additional user configuration to achieve the desired result.
I don’t have any .themes or .icons folder on KDE Minimal Manjaro install. I also tried copying the folders and giving those permissions, but that did not also work.
Would installing full Manjaro possibly fix the issue? I wouldn’t want to do that cause all the account configurations etc., but i guess i could do it.
Those directories don’t exist by default, but you can create them and you can put themes in them. It’s how users can add their own themes.
No, I would expect not. It’s a configuration issue, you haven’t configured things yet.
You have to create the directories, put your themes in them, configure flatpak to have access to the directories and then configure flatpak to use the themes that you want.
Another option is to not use flatpaks.
Before with full install of Manjaro i had theming done for QT apps out of the box with Flatpak. With that guides QT settings don’t do any theming whatsoever. Even though when i delete the kvantum Flatpak install it says that it’s used by OBS.
Could it be that something has changed in Manjaro that prevents the theming? Cause before i could have the theming applied with no configuration at all for QT apps.
Not using Flatpaks is not really an option for me on Manjaro cause OBS lacks VAAPI for the repo install, also glibc breakage with EAC games with Steam is prevented by the use of Flatpak.
Well I could be wrong, perhaps someone already configured it in the full version.
Simply creating these folders will do nothing.
No.
You should adapt the advice given in that guide - link to your system themes and icons instead
or just copy them there … now you will have unnecessarily duplicated the content, but the guide will work as is 
You don’t need to manually create those directories. They are created automatically if you install any additional gtk themes via the GUI.
qt themes are generally stored under ~/.local/share somewhere, but gtk insists on using ~/.themes and ~/.icons.
I have copied the files.
I have followed the guide. Seems like there is no GTK theme for Manjaros Breathe dark theme so nothing to go from there. QT app guide still doesn’t work for OBS. The guide works probably, but not for Manjaro. Even if i set breeze-dark theme, Flatseal will still show me white theme of Adwaita.
No, indeed there isn’t.
breath-dark is a color scheme within plasma - not a GTK theme
In my VM default installation, it’s mentioned in ~/.config/kdedefaults/plasmarc
in every single file in that directory, actually
Breeze seems to be the base of it.
I have zero experience with Flatpaks and very little with KDE Plasma.
I don’t know how that theming works there.
Can’t help.
Sorry.
You could be missing the optional components for flatpak
sudo pacman -Syu flatpak-kcm flatpak-xdg-utils
Package lists for full and minimal ISOs include 2 flatpak packages:
flatpak 1:1.16.0-2
libpamac-flatpak-plugin 11.7.3-4
so OP probably is missing optional components