# Dolphin Theming Help QT

**URL:** https://discourse.nixos.org/t/dolphin-theming-help-qt/68407
**Category:** Help
**Created:** [August 24, 2025, 1:18am UTC](https://discourse.nixos.org/t/dolphin-theming-help-qt/68407 "2025-08-24T01:18:08Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![caret](https://discourse.nixos.org/user_avatar/discourse.nixos.org/caret/32/16037_2.png) [@caret](https://discourse.nixos.org/u/caret)
#### Post date: [August 24, 2025, 1:18am UTC](https://discourse.nixos.org/t/dolphin-theming-help-qt/68407/1 "2025-08-24T01:18:08Z")

</div>

After updating to nix 25.05 my theming mechanisms; I simply followed the example in this post. And now after updating its not working the way it used to.

```nix
environment.systemPackages = with pkgs;
  [
    libsForQt5.qtstyleplugin-kvantum
    libsForQt5.qt5ct
];
nixpkgs.config.qt5 = {
  enable = true;
  platformTheme = "qt5ct"; 
    style = {
      package = pkgs.utterly-nord-plasma;
      name = "Utterly Nord Plasma";
    };
};

```

I’m struggling on getting this working. I tried it for qt6, same issue. Nothing is taking. I don’t want to use stylix or home-manager (yet), I want something simple and works (as simple as the thing that used to work above). I just want everything in a dark theme, I don’t really care what at this point. Any ideas?

Also tried this:

```nix
  # night theme environment vars
  nixpkgs.config.qt6 = {
    enable = true;
    platformTheme = "qt6ct"; 
      style = {
        package = pkgs.utterly-nord-plasma;
        name = "Utterly Nord Plasma";
      };
  };
  environment.variables.QT_QPA_PLATFORMTHEME = "qt6ct";

```

Relevant packages enabled in my package list:

```auto
	lxappearance
	kdePackages.gwenview
  adwaita-qt
  adwaita-qt6
	materia-theme
	libsForQt5.ffmpegthumbs
	libsForQt5.kio-extras
	libsForQt5.kdegraphics-thumbnailers
	libsForQt5.qtstyleplugin-kvantum
  qt6Packages.qtstyleplugin-kvantum
	kdePackages.polkit-kde-agent-1
	kdePackages.dolphin
	kdePackages.qt6ct
	kdePackages.kde-cli-tools
	kdePackages.breeze-icons
	kdePackages.ark
	kdePackages.ark
	kdePackages.xdg-desktop-portal-kde
	kdePackages.kleopatra
  kdePackages.full

```

This is on an i3 setup fwiw

Referenced Post:

> [@Guide to installing qt theme](https://discourse.nixos.org/t/guide-to-installing-qt-theme/35523/2):
>
> Hey fellow Nix enthusiasts! star2 If you are venturing into the beautiful world of Nix and want to spruce up your Qt applications with a theme, here is a simple guide to get you started: wrench System Configuration wrench environment.systemPackages = with pkgs; [libsForQt5.qtstyleplugin-kvantum libsForQt5.qt5ct]; nixpkgs.config.qt5 = { enable = true; platformTheme = "qt5ct"; style = { package = pkgs.utterly-nord-plasma; name = "Utterly Nord Plasma"; …

---

<div class="post-metadata">

### Author: ![Frontear](https://discourse.nixos.org/user_avatar/discourse.nixos.org/frontear/32/27055_2.png) [@Frontear](https://discourse.nixos.org/u/Frontear)
#### Post date: [August 24, 2025, 2:32am UTC](https://discourse.nixos.org/t/dolphin-theming-help-qt/68407/2 "2025-08-24T02:32:16Z")

</div>

I’m pretty sure qt6ct doesn’t just automatically set the theme. Idk if home-manager manually configures by writing the theme name into its config. If not, run qt6ct in your terminal, then select the theme and close.

Also don’t set `QT_QPA_PLATFORMTHEME` manually, the home manager module does that for you.

---

<div class="post-metadata">

### Author: ![anon77591810](https://discourse.nixos.org/letter_avatar_proxy/v4/letter/a/b5e925/32.png) [@anon77591810](https://discourse.nixos.org/u/anon77591810)
#### Post date: [January 15, 2026, 7:46pm UTC](https://discourse.nixos.org/t/dolphin-theming-help-qt/68407/3 "2026-01-15T19:46:15Z")

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Hello!

This setup configures Qt theming minimal declaratively, at the system level.  
It works for Qt5 and Qt6, does not require Home Manager, and does not rely on GUI tools.

```auto
{ pkgs, ... }:
{
  environment = {
    systemPackages = with pkgs; [
      libsForQt5.qt5ct
      kdePackages.qt6ct
      adwaita-qt
    ];
    sessionVariables = {
      QT_QPA_PLATFORMTHEME = "qt5ct";
    };
    etc = {
      "xdg/qt5ct/qt5ct.conf".text = ''
        [Appearance]
        style=adwaita-dark
      '';
      "xdg/qt6ct/qt6ct.conf".text = ''
        [Appearance]
        style=adwaita-dark
      '';
    };
  };
}

```