shaunguimond.com / cobalt_11_theme
A Windows 11 style Global Theme for KDE Plasma 6. It is a personal fork of yeyushengfan258's Win11OS-dark.
Star 0
Fork 0
Watch
Python 51%
35%
QML 14%
19 1 0
agent
backups
scripts
src
.gitignore
LICENSE
README.md
README.md

Cobalt 11 Theme #

A Windows 11 style Global Theme for KDE Plasma 6.

Named after Cobalt, the internal codename for the Windows 11 project.

It currently ships a dark variant (Cobalt 11 Dark). The naming is deliberately generic. You can add a light variant alongside it later.

Companion project: Cobalt 11 Launcher, a Windows 11 style application launcher.

What this provides #

Component Package Installs to
Global Theme (Look & Feel) com.shaunguimond.cobalt11.dark ~/.local/share/plasma/look-and-feel/
Plasma Style Cobalt11-dark ~/.local/share/plasma/desktoptheme/
Colour scheme Cobalt11Dark.colors ~/.local/share/color-schemes/

Why this fork exists #

The upstream theme had a bug that silently disabled colour theming across the whole desktop. Plasma recolours theme SVGs at runtime. It replaces the stylesheet anchored at id="current-color-scheme". 28 of the SVGs carried a second <style> block. This block repeated the same rules with hardcoded Breeze Light values. It appeared later with equal specificity. The CSS cascade discarded every substituted colour.

The visible result was white tooltips with near-white text on a dark theme. Hover overlays ignored the colour scheme entirely. I removed 53 duplicate blocks across 28 files.

Full analysis: agent/docs/SVG Color Substitution.md.

Also fixed:

  • Hover overlays now use ColorScheme-Text at low opacity. They follow the active scheme instead of being pinned to hardcoded white.
  • Tooltip frame elements that had no colour class at all.
  • A dangling ColorScheme=VimixDarkDoder reference to a scheme that does not exist on disk.
  • Defaults no longer force widgetStyle=kvantum or a cursor theme that the package does not ship.

Dependencies #

These are not vendored. Install them separately if you want the complete look.

Icons (required for the intended appearance) #

The Global Theme sets the icon theme to Win11-dark from yeyushengfan258/Win11-icon-theme (GPL-3.0). It is roughly 80 MB across ~35,000 unmodified files, so it is not redistributed here.

The easiest route is System Settings -> Appearance -> Icons -> Get New Icons. Search for Win11 and install. That provides Win11 and Win11-dark.

Or from source:

git clone https://github.com/yeyushengfan258/Win11-icon-theme.git
cd Win11-icon-theme && ./install.sh

The source installer can produce differently named variants (for example Win11-black-dark). If your icon theme is named differently, pick it in System Settings after applying the Global Theme. Or edit the Theme= line under [kdeglobals][Icons] in contents/defaults before installing.

Without the icons, Plasma falls back to your current icon theme. Everything else still works.

Window decoration (optional) #

Defaults reference the Aurorae theme Win11OS-dark from yeyushengfan258/Win11OS-kde. If absent, KWin falls back to Breeze.

Wallpaper (not included) #

The upstream package shipped the Windows 11 "Bloom" wallpaper. That artwork is Microsoft's. It cannot be redistributed under the GPL regardless of how the upstream package labelled it. It is not present here. Set any wallpaper you like.

Installation #

git clone https://tangled.org/shaunguimond.com/cobalt_11_theme
cd cobalt_11_theme

kpackagetool6 --type Plasma/LookAndFeel --install src/look-and-feel/com.shaunguimond.cobalt11.dark
kpackagetool6 --type Plasma/Theme      --install src/plasma-theme/Cobalt11-dark
mkdir -p ~/.local/share/color-schemes
cp src/colors/Cobalt11Dark.colors ~/.local/share/color-schemes/

Apply via System Settings → Appearance → Global Theme → Cobalt 11 Dark, or:

plasma-apply-lookandfeel   -a com.shaunguimond.cobalt11.dark
plasma-apply-desktoptheme  Cobalt11-dark
plasma-apply-colorscheme   Cobalt11Dark

Upgrading #

kpackagetool6 --type Plasma/LookAndFeel --upgrade src/look-and-feel/com.shaunguimond.cobalt11.dark
kpackagetool6 --type Plasma/Theme      --upgrade src/plasma-theme/Cobalt11-dark

Removing #

kpackagetool6 --type Plasma/LookAndFeel --remove com.shaunguimond.cobalt11.dark
kpackagetool6 --type Plasma/Theme      --remove Cobalt11-dark
rm ~/.local/share/color-schemes/Cobalt11Dark.colors

Development #

Symlink the packages so edits apply on restart without reinstalling:

ln -s "$PWD/src/plasma-theme/Cobalt11-dark" ~/.local/share/plasma/desktoptheme/Cobalt11-dark
ln -s "$PWD/src/look-and-feel/com.shaunguimond.cobalt11.dark" ~/.local/share/plasma/look-and-feel/com.shaunguimond.cobalt11.dark

Plasma caches rendered SVGs. Restarting plasmashell alone is not enough. Edits will appear to do nothing until you clear the caches:

killall plasmashell
rm -f ~/.cache/plasma_theme_*.kcache ~/.cache/ksvg-elements
(setsid plasmashell >/dev/null 2>&1 &)

Maintenance scripts:

python3 scripts/fix-duplicate-stylesheets.py   # strip stylesheet blocks that break recolouring
python3 scripts/fix-hover-colors.py            # normalise hover overlays to ColorScheme-Text

Both are idempotent. Both write backups outside the package.

Detailed notes live in agent/.

Credits #

Built on yeyushengfan258's work, all GPL-3.0:

Project Purpose
Win11OS-kde Plasma Style, Aurorae decoration
Win11OS-dark-kde Global Theme
Win11-icon-theme Icons (dependency, not vendored)

The icon theme is itself derived from Ubuntu Yaru.

Licence #

GPL-3.0-or-later, matching upstream. See LICENSE.

Windows and Windows 11 are trademarks of Microsoft Corporation. This project is an independent visual theme. It is not affiliated with or endorsed by Microsoft. It ships no Microsoft artwork.