NiceOS9 KDE Plasma Theme — v5.1.0

Two KDE Plasma look-and-feel themes inspired by classic Mac OS 9 aesthetics.

Variants

Theme	Color Scheme	Window Decoration	Cursor	Plasma Shell
NiceOS9 dark	NiceOS9Dark	ChicagoNineDark (Aurorae)	Breeze	niceos9-dark
NiceOS9 bright	ChicagoNineLight	ChicagoNine (Aurorae)	XCursor-Pro-Red	niceos9-bright

Both themes use:

• Icons: nineicons-redux-v0.6
• Widget style: Fusion (built-in Qt)
• Font: ChicagoFLF (public domain, by Robin Casady)

What's included

look-and-feel/     — NiceOS9 dark + NiceOS9 bright global theme packages
  contents/
    lockscreen/    — Mac OS 9 Finder Greeter for kscreenlocker (plasmalogin)
wallpapers/        — shared wallpaper assets, generated variants, and wallpaper roadmap
    layouts/       — desktop layout JS
desktoptheme/      — niceos9-dark + niceos9-bright Plasma desktop themes (panel/taskbar assets + colors)
plasma/            — legacy shell theme sources kept for compatibility
color-schemes/     — NiceOS9Dark.colors, ChicagoNineLight.colors
aurorae/           — ChicagoNine (bright) + ChicagoNineDark (dark) window decorations
icons/             — nineicons-redux-v0.6 icon theme
cursors/           — XCursor-Pro-Red cursor theme (used by bright)
fonts/             — ChicagoFLF.ttf (public domain)
plymouth/          — niceos9-plymouth boot screen (Happy Mac, Plymouth Script plugin)
grub/              — niceos9-grub boot menu (Mac OS 9 Platinum desktop background)
sddm/              — niceos9-sddm login screen (Finder Greeter, for systems using SDDM)
previews/          — HTML design mockups for boot + login screen variants

Installation

From KDE Look (zip download)

1. Extract the zip archive
2. Open a terminal inside the extracted folder
3. Run the installer:

chmod +x install.sh
./install.sh

4. Open System Settings → Colors & Themes → Global Theme
5. Select NiceOS9 dark or NiceOS9 bright and click Apply

From GitHub

git clone https://github.com/huppiflupp/NiceOS9-theme.git
cd NiceOS9-theme
chmod +x install.sh
./install.sh

Uninstall / stale-file cleanup

To remove the NiceOS9 files installed by this project:

chmod +x uninstall.sh
./uninstall.sh

This removes the local Plasma theme assets, the old stale look-and-feel/NiceOS9 ... package directories, and the optional system-wide SDDM, Plymouth, and GRUB theme directories if they were installed.

Manual installation

If you prefer to install components individually, copy each folder to the corresponding location in your home directory:

Source	Destination
look-and-feel/niceos9-dark	~/.local/share/plasma/look-and-feel/
look-and-feel/niceos9-bright	~/.local/share/plasma/look-and-feel/
desktoptheme/niceos9-dark	~/.local/share/plasma/desktoptheme/
desktoptheme/niceos9-bright	~/.local/share/plasma/desktoptheme/
wallpapers/NiceOS9	~/.local/share/wallpapers/
color-schemes/*.colors	~/.local/share/color-schemes/
aurorae/ChicagoNine	~/.local/share/aurorae/themes/
aurorae/ChicagoNineDark	~/.local/share/aurorae/themes/
icons/nineicons-redux-v0.6	~/.local/share/icons/
cursors/XCursor-Pro-Red	~/.icons/
fonts/ChicagoFLF.ttf	~/.local/share/fonts/

After copying fonts run: fc-cache -f ~/.local/share/fonts/

Then open System Settings → Colors & Themes → Global Theme and select NiceOS9 dark or NiceOS9 bright.

Note: The installer sets up wallpaper paths and kscreenlocker config automatically. If you install manually, run the kwriteconfig6 commands in install.sh (search for kscreenlockerrc) to configure the lock screen background.

---

Panel / taskbar (Plasma shell theme)

The panel color is controlled by the Plasma shell theme — separate from the application color scheme and the look-and-feel package itself.

Theme	Plasma shell	Panel background	Panel text
NiceOS9 dark	niceos9-dark	#2c2a28 dark warm charcoal	cream white
NiceOS9 bright	niceos9-bright	#c8c4bc Platinum gray	black

install.sh copies both desktop themes to ~/.local/share/plasma/desktoptheme/. The defaults files in each look-and-feel package reference them so they apply automatically when you select the global theme.

The panel is also forced to non-floating mode by the autostart script autostart/panel-nofloat.sh (installed to ~/.local/bin/ and registered in ~/.config/autostart/). Plasma 6 resets floating mode on each session start, so the autostart runs 4 seconds after login and keeps only floating = false. Panel height is now user-editable after install. The installer also supports an initial default height with NICEOS9_PANEL_HEIGHT=40 ./install.sh.

Adjusting panel colors

The shell themes are plain text files. To tune the panel background:

# Edit the colors file
nano ~/.local/share/plasma/desktoptheme/niceos9-bright/colors
# Change Colors:Complementary > BackgroundNormal to your preferred R,G,B
# Then restart Plasma shell to apply:
plasmashell --replace &

---

Lock screen (plasmalogin / kscreenlocker)

On Nobara and most modern KDE setups, plasmalogin is the display manager. When you lock your session, plasmalogin hands off to kscreenlocker, which loads the lock screen UI from the active look-and-feel's contents/lockscreen/ directory.

The NiceOS9 lock screen renders the same Mac OS 9 Finder Greeter as the SDDM theme:

• Mac OS 9 menu bar at the top with live clock
• Platinum-chrome login window with user avatar, password field and Unlock button
• NiceOS9 wallpaper as background from the shared ~/.local/share/wallpapers/NiceOS9/ install
• Current defaults: Flowing_Indigo_Wave.png for dark and Flowing_Platinum_Wave.png for bright

Test without locking your session:

/usr/libexec/kscreenlocker_greet --testing

Press any key or move the mouse to show the password prompt. Press Escape to dismiss.

How the background works

kscreenlocker renders a wallpaper layer (from ~/.config/kscreenlockerrc) below the QML. install.sh updates that key to the NiceOS9 wallpaper so there is no flash of a foreign background on slow hardware. The QML itself also renders the wallpaper directly as an Image item — no dependency on the wallpaper context property, which was how Nobara's background was bleeding through before.

Do not replace the Image with WallpaperFader { source: wallpaper }. The wallpaper context property reads from kscreenlockerrc (defaults to Nobara's image). WallpaperFader { source: someItem } also silently fails if the item source hasn't rendered to a layer yet, leaving the compositor background visible.

Key files to edit if you want to change the lock screen

File	What it controls
look-and-feel/niceos9-dark/contents/lockscreen/LockScreenUi.qml	Background image, menu bar, lifecycle, opacity animations
look-and-feel/niceos9-dark/contents/lockscreen/MainBlock.qml	Platinum login window, avatar, password field, Unlock button
look-and-feel/niceos9-dark/contents/lockscreen/MacButton.qml	Shared Mac OS 9 button component
look-and-feel/niceos9-dark/contents/lockscreen/LockScreen.qml	Root container — exposes kscreenlocker's required API (do not change without reading kscreenlocker docs)

After editing, redeploy with:

cp -r look-and-feel/niceos9-dark ~/.local/share/plasma/look-and-feel/
cp fonts/ChicagoFLF.ttf ~/.local/share/plasma/look-and-feel/niceos9-dark/contents/lockscreen/

---

Login screen (SDDM)

Note: On Nobara and other systems using plasmalogin, the initial login screen (before your session starts) uses a binary-compiled greeter — plasma-login-greeter. Its UI is embedded in the executable and cannot be themed via QML. Only its background wallpaper is configurable (via /etc/plasmalogin.conf or System Settings → Security → Screen Locking).

The SDDM theme below applies to systems that actually use SDDM as their display manager.

The sddm/niceos9-sddm/ theme renders a Mac OS 9 "Finder Greeter": platinum menu bar with live clock, blue Finder desktop, and a Mac OS 9-style login dialog with beveled title bar, user avatar, and styled buttons.

Install requires root (SDDM themes are system-wide):

sudo cp -r sddm/niceos9-sddm /usr/share/sddm/themes/

Activate — either via System Settings → Colors & Themes → Login Screen (SDDM), or directly:

sudo mkdir -p /etc/sddm.conf.d
echo -e "[Theme]\nCurrent=niceos9-sddm" | sudo tee /etc/sddm.conf.d/niceos9.conf

On Ubuntu-based Plasma systems such as KDE neon, SDDM is usually still the display manager, so the SDDM theme above is the path that matters. On Fedora derivatives such as Nobara, check first whether the system is using sddm or plasmalogin.

---

Boot screen (Plymouth)

The plymouth/niceos9-plymouth/ theme shows a classic compact Mac face ("Happy Mac") on a platinum gray background with an animated candy-stripe progress bar, rendered in ChicagoFLF.

Install requires root (Plymouth themes are system-wide):

# Generate PNG assets (Pillow required: pip install Pillow)
python3 plymouth/niceos9-plymouth/generate-assets.py

# Copy to system and activate
sudo mkdir -p /usr/share/plymouth/themes/niceos9-plymouth
sudo cp plymouth/niceos9-plymouth/*.png \
        plymouth/niceos9-plymouth/niceos9.script \
        plymouth/niceos9-plymouth/niceos9-plymouth.plymouth \
        /usr/share/plymouth/themes/niceos9-plymouth/
sudo plymouth-set-default-theme niceos9-plymouth
sudo update-initramfs -u   # Ubuntu / Debian / KDE neon
# or:
sudo dracut -f

The generate-assets.py script uses the bundled ChicagoFLF font to bake text into PNGs so no font is needed inside the initramfs.

Applying changes after editing the theme

Plymouth is embedded into the initramfs, so editing source files has no effect until you reinstall and rebuild it. After any change to files in plymouth/niceos9-plymouth/:

python3 plymouth/niceos9-plymouth/generate-assets.py
sudo cp plymouth/niceos9-plymouth/*.png \
        plymouth/niceos9-plymouth/niceos9.script \
        plymouth/niceos9-plymouth/niceos9-plymouth.plymouth \
        /usr/share/plymouth/themes/niceos9-plymouth/
sudo plymouth-set-default-theme niceos9-plymouth
sudo update-initramfs -u   # Ubuntu / Debian / KDE neon
# or:
sudo dracut -f             # Fedora / Nobara

Rebuilding the initramfs takes 30–60 seconds. The updated animation appears on the next reboot.

---

GRUB boot menu

The grub/niceos9-grub/ theme shows a 1920×1080 platinum Mac OS 9 desktop as the GRUB background: a menu bar at the top, a large Happy Mac centred on screen, the "NiceOS 9" title, and a "Select a startup volume:" prompt — with the boot entry list appearing below as a Mac OS 9-style dialog window.

Install requires root (GRUB themes are system-wide):

# Generate PNG assets (Pillow required: pip install Pillow)
python3 grub/niceos9-grub/generate-assets.py

# Copy to system
sudo mkdir -p /boot/grub/themes/niceos9-grub     # Ubuntu / Debian / KDE neon
# or:
sudo mkdir -p /boot/grub2/themes/niceos9-grub    # Fedora / Nobara
sudo cp grub/niceos9-grub/*.png grub/niceos9-grub/theme.txt /boot/grub/themes/niceos9-grub/
# or:
sudo cp grub/niceos9-grub/*.png grub/niceos9-grub/theme.txt /boot/grub2/themes/niceos9-grub/

# Generate PF2 fonts from ChicagoFLF
# Use grub-mkfont on Ubuntu/Debian, or grub2-mkfont on Fedora if that is the installed name.
sudo grub-mkfont -s 18 -n "ChicagoFLF 18" \
    -o /boot/grub/themes/niceos9-grub/ChicagoFLF-18.pf2 fonts/ChicagoFLF.ttf
sudo grub-mkfont -s 14 -n "ChicagoFLF 14" \
    -o /boot/grub/themes/niceos9-grub/ChicagoFLF-14.pf2 fonts/ChicagoFLF.ttf
# or on Fedora/Nobara:
sudo grub2-mkfont -s 18 -n "ChicagoFLF 18" \
    -o /boot/grub2/themes/niceos9-grub/ChicagoFLF-18.pf2 fonts/ChicagoFLF.ttf
sudo grub2-mkfont -s 14 -n "ChicagoFLF 14" \
    -o /boot/grub2/themes/niceos9-grub/ChicagoFLF-14.pf2 fonts/ChicagoFLF.ttf

Activate — add the theme line to /etc/default/grub, then rebuild:

# Ubuntu / Debian / KDE neon:
GRUB_THEME='/boot/grub/themes/niceos9-grub/theme.txt'
sudo update-grub

# Fedora / Nobara:
GRUB_THEME='/boot/grub2/themes/niceos9-grub/theme.txt'
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Fedora / Nobara note: the config file is /boot/grub2/grub.cfg on BIOS and /boot/efi/EFI/fedora/grub.cfg on UEFI. Use whichever matches your system.

Applying changes after editing the theme

python3 grub/niceos9-grub/generate-assets.py
sudo cp grub/niceos9-grub/*.png /boot/grub/themes/niceos9-grub/
sudo update-grub

# or on Fedora / Nobara:
sudo cp grub/niceos9-grub/*.png /boot/grub2/themes/niceos9-grub/
sudo grub2-mkconfig -o /boot/grub2/grub.cfg