Flatpak Theming

### Compositor

Niri

### If Other, please specify

_No response_

### Distribution

Arch Linux

### If Other, please specify

_No response_

### Select your Installation Method

DankInstaller

### Was your original Installation method different?

No (specify below)

### If no, specify

_No response_

### dms doctor -vC

Click to expand
## DMS Doctor Report

**System**
- [ok] Operating System: Arch Linux
- ID: arch, Version: rolling, Arch: amd64
- [ok] Architecture: amd64
- [ok] Display Server: Wayland
- WAYLAND_DISPLAY=wayland-1

**Versions**
- [ok] DMS CLI: dms v1.4.4.1
- /usr/bin/dms
- [warn] Quickshell: Quickshell 0.2.1 (revision fb08eced449e87e47321e95beeb890a63d2c67bd, distributed by AUR (package: quickshell-git))
- /usr/bin/qs
- [ok] DMS Shell: v1.4.4
- /usr/share/quickshell/dms

**Installation**
- [ok] DMS Configuration: Found
- /usr/share/quickshell/dms
- [ok] shell.qml: Present
- /usr/share/quickshell/dms/shell.qml
- [info] Install Type: System package
- /usr/share/quickshell/dms

**Compositor**
- [ok] niri: 25.11
- /usr/bin/niri
- [info] Active: niri

**Quickshell Features**
- [ok] Polkit: Available
- Authentication prompts
- [ok] IdleMonitor: Available
- Idle detection
- [ok] IdleInhibitor: Available
- Prevent idle/sleep
- [ok] ShortcutInhibitor: Available
- Allow shortcut management (niri)

**Optional Features**
- [ok] accountsservice: Available
- User accounts
- [ok] power-profiles-daemon: Available
- Power profile management
- [ok] logind: Available
- Session management
- [ok] cups-pk-helper: Available
- Printer management
- [info] I2C/DDC: No monitors detected
- External monitor brightness control
- [ok] qt6-imageformats: Installed (1 formats)
- Formats: GIF (/usr/lib/qt6/plugins/imageformats:/usr/lib64/qt6/plugins/imageformats)
- [ok] kimageformats: Installed (4 formats)
- Formats: AVIF, HEIF, JXL, EXR (/usr/lib/qt6/plugins/imageformats:/usr/lib64/qt6/plugins/imageformats)
- [ok] Terminal: kitty
- [ok] Network: iwd + systemd-networkd
- iwd + systemd-networkd detected. Using iwd for Wi-Fi association and networkd for IP/DHCP.
- [ok] matugen: Installed
- Dynamic theming
- [ok] dgop: Installed
- System monitoring
- [ok] cava: Installed
- Audio visualizer
- [ok] khal: Installed
- Calendar events
- [ok] danksearch: Installed
- File search
- [ok] fprintd: Installed
- Fingerprint auth

**Config Files**
- [ok] settings.json: Present
- /home/mitu/.config/DankMaterialShell/settings.json
- [ok] clsettings.json: Present
- /home/mitu/.config/DankMaterialShell/clsettings.json
- [ok] plugin_settings.json: Present
- /home/mitu/.config/DankMaterialShell/plugin_settings.json
- [ok] session.json: Present
- /home/mitu/.local/state/DankMaterialShell/session.json
- [ok] dms-colors.json: Present
- /home/mitu/.cache/DankMaterialShell/dms-colors.json

**Services**
- [ok] dms.service: enabled, active
- [info] greetd: Not installed
- Optional greeter service

**Environment**
- [info] QT_QPA_PLATFORMTHEME: Not set
- [info] QS_ICON_THEME: Not set

---
**Summary:** 0 error(s), 1 warning(s), 32 ok

### Description

Themes are not applied to Flatpak Applications

### Solutions Tried

I already tried to give the Apps access to .config/gtk-X.0/

That did nothing

When linking those files into a new Theme inside .themes and setting the Theme using Environments (GTK_THEME), the Applications just went completely Transparent.

### Configuration Details

_No response_

### Screenshots/Recordings

_No response_

Start by reproducing Flatpak theming on Arch Linux with DankMaterialShell under niri, using the reported dms doctor -vC output as context. Review the mentioned settings.json, clsettings.json, plugin_settings.json, and environment settings; no source file or test is identified. Done means Flatpak applications visibly receive the intended theme without becoming transparent.

Written by the indexing model from the issue text.