PixelKit

PixelKit is a native Linux implementation of the Microsoft PowerToys Color Picker and Screen Ruler workflows. It is written in Rust, ships as one small process-on-demand binary, stores everything locally, and supports both X11 and Wayland without privileged input or capture hooks.

PixelKit is independent of Microsoft and PowerToys. PowerToys was used as the MIT-licensed behavioral reference included beside this project.

See PixelKit in action

Screencast_20260715_141803_trimmed_54s.mp4

Features

Color Picker, Magnifier, and editor

• Pick any captured pixel with an always-on-top full-screen overlay.
• 13×13 loupe with tooltip and pointer-centered styles with up to 255 wheel-controlled zoom levels.
• Standalone magnifier with centered-grid and tooltip styles plus configurable starting/maximum zoom, grid size, cursor, Wayland capture behavior, and global shortcut.
• Arrow-key movement at one pixel; Shift+arrow movement at ten pixels.
• Primary, middle, and secondary click actions: pick then edit, pick and close, or close without copying.
• Enter/Space to pick and Escape/Backspace to cancel; Escape also closes the editor opened after a pick.
• Full-resolution, losslessly tiled capture rendering on displays larger than the GPU's single-texture limit.
• Persistent, de-duplicated history with configurable limit.
• Editable RGB and HSV controls, three/six-digit HEX input, and four related color variations.
• Nearest human-readable color names using the PowerToys bucket algorithm.
• Export history as JSON or text, grouped by color or by format.
• Sixteen built-in representations: HEX, RGB, HSL, HSV, CMYK, HSB, HSI, HWB, NCol, CIE XYZ, CIE LAB, Oklab, Oklch, VEC4, Decimal, and HEX Int.
• PowerToys-compatible custom format tokens such as %ReX, %Gr, %Hu, %Sl, %Na, and the full CIE/Oklab parameter set.

Screen Ruler

• Bounds/rectangle measurement.
• Cross, horizontal, and vertical same-color spacing measurement.
• Sum-of-RGB or per-channel edge tolerance, directly typeable from 0–255 and adjustable by mouse wheel in 15-point steps.
• Configurable crosshair color and end caps.
• Pixels, inches, centimetres, and millimetres, using X11 physical display data or a configurable Wayland fallback DPI.
• Shift-click retains multiple measurements; clipboard output contains every retained measurement.
• Touch/pointer input, right-click cancellation, Ctrl+1…4 tool selection, and non-blocking snapshot recapture.
• X11 continuous capture uses a transparent blank/capture cycle so PixelKit's own lines are excluded from the sampled image.

Linux integration

• Direct, low-latency X11 root capture and native key grabs.
• xdg-desktop-portal Screenshot and GlobalShortcuts interfaces on Wayland and inside Flatpak.
• A lightweight background mode that does no screen polling while idle.
• Desktop actions, AppStream metadata, scalable and high-resolution icons, man page, and systemd user unit.
• No telemetry, cloud service, network request, root helper, or setuid binary.

The Fedora 44 x86_64 reference build is a 9.2 MB stripped executable. The X11 shortcut daemon settles at roughly 5.6 MB RSS and blocks on events while idle; it does not initialize the GUI or capture a screen until a tool is launched.

X11 and Wayland behavior

Capability	X11	Wayland / Flatpak
Screen capture	Immediate direct capture	Screenshot portal; the compositor may ask for permission or a target
Pixel and ruler overlay	Full captured desktop	Portal snapshot scaled into a full-screen precision canvas
Global shortcuts	X11 key grab	GlobalShortcuts portal; compositor chooses/grants the final binding
Continuous ruler background	Live transparent recapture	Manual Recapture / R after underlying content changes, because the Screenshot portal is intentionally request-based
Clipboard	Native X11 selection	Native Wayland data control plus GUI clipboard fallback

Wayland does not let ordinary applications silently read other windows or install global input hooks. PixelKit respects that boundary. A portal dialog is part of the desktop security model, not a missing package permission. On a desktop without the GlobalShortcuts portal, assign these commands in the desktop's keyboard settings:

pixelkit color-picker
pixelkit magnifier
pixelkit screen-ruler

Install from package repositories

Published x86_64 packages are available from the Fedora Copr repository and the openSUSE Build Service project. Arch Linux users can build PixelKit from its AUR package.

Fedora 44 and Rawhide

sudo dnf copr enable kuchen/pixelkit
sudo dnf install pixelkit

Arch Linux (AUR)

Install with an AUR helper such as yay:

yay -S pixelkit

Or build and install the package manually:

git clone https://aur.archlinux.org/pixelkit.git
cd pixelkit
makepkg -si

Debian 13 and Ubuntu 24.04/26.04

Set repo to the entry matching the installed distribution, then add the OBS signing key and APT source:

repo=xUbuntu_24.04 # Debian_13, xUbuntu_24.04, or xUbuntu_26.04
base="https://download.opensuse.org/repositories/home:/kuchen:/PixelKit/$repo"

sudo apt install curl gpg
sudo install -d -m 0755 /etc/apt/keyrings
curl -fsSL "$base/Release.key" | gpg --dearmor | \
  sudo tee /etc/apt/keyrings/pixelkit-obs.gpg >/dev/null
echo "deb [signed-by=/etc/apt/keyrings/pixelkit-obs.gpg] $base/ /" | \
  sudo tee /etc/apt/sources.list.d/pixelkit-obs.list
sudo apt update
sudo apt install pixelkit

The OBS signing-key fingerprint is C246 A272 BD2F B2A0 4044 ECDA C7C1 26FB 1D6D 878E.

Install from source

Rust 1.88 or newer, GCC, make, and normal X11/Wayland/OpenGL runtime libraries are required. Rust dependencies do not require GTK or Qt development headers.

cargo test --all-targets --locked
cargo build --release --locked
sudo make install

For a user-only installation:

./scripts/install-user.sh

Run PixelKit

Launch pixelkit, or use a direct command:

pixelkit color-picker
pixelkit magnifier
pixelkit color-editor
pixelkit screen-ruler

Enable background shortcuts for native packages:

systemctl --user enable --now pixelkit.service

On Wayland, the desktop owns the active key combinations. If it registered the actions without assigning keys, open its PixelKit shortcut page with:

pixelkit configure-shortcuts

Packaging

The repository includes source-build definitions for the major Linux package families. Release builders use the locked dependency graph; distro builds can use the vendored source archive produced by make dist and need no network inside the build sandbox.

The normal entry point is the package orchestrator. It refreshes Flatpak's locked Cargo source hashes, runs the available checks once, reuses the release binary where possible, and writes a verified dist/SHA256SUMS:

./scripts/build-packages.sh --list
./scripts/build-packages.sh

With no format arguments it builds every format supported by tools installed on the current host. Explicit selections are strict, for example ./scripts/build-packages.sh rpm deb. For a real upstream release, use:

./scripts/build-packages.sh --clean --set-version 0.1.1

This updates Cargo, the lockfile, distro package definitions, Flatpak, Snap, Nix, AppStream, and the manual page, then resets RPM/Debian/Arch package revisions for the new version. For another package revision of the same upstream version, use --bump "Short changelog summary" instead. Neither option commits, tags, pushes, or publishes anything.

make packages is a shorthand, with optional arguments supplied through PACKAGE_ARGS. If an RPM builder is installed without the spec's development packages, --list reports the missing package names; on Fedora they can all be installed with sudo dnf builddep packaging/rpm/pixelkit.spec.

Ecosystem	Definition	Build command
Flatpak / Flathub	packaging/flatpak/	./scripts/build-packages.sh flatpak
Fedora / RHEL / DNF	packaging/rpm/pixelkit.spec	./scripts/build-packages.sh rpm
openSUSE / Zypper	packaging/opensuse/pixelkit.spec	./scripts/build-packages.sh opensuse
Debian / Ubuntu / APT	debian/	./scripts/build-packages.sh deb-source
Arch / pacman / AUR	packaging/arch/PKGBUILD	./scripts/build-packages.sh arch
Snap Store	snap/snapcraft.yaml	./scripts/build-packages.sh snap
Nix / NixOS	flake.nix	./scripts/build-packages.sh nix
AppImage	packaging/appimage/build-appimage.sh	./scripts/build-packages.sh appimage

See Packaging and release guide for namespace ownership, checksums, repository submission, and validation details.

Configuration

Settings use readable, version-tolerant JSON:

• ${XDG_CONFIG_HOME:-~/.config}/pixelkit/settings.json
• ${XDG_DATA_HOME:-~/.local/share}/pixelkit/history.json

Run pixelkit paths to print the exact locations. Corrupt settings never erase history; the UI reports save errors and falls back to safe defaults.

Development and tests

cargo check --all-targets --locked
cargo test --all-targets --locked
cargo run -- formats '#ff0000'
cargo run -- color-picker --image test-screen.png
cargo run -- magnifier --image test-screen.png
cargo run -- screen-ruler --image test-screen.png

The --image mode exercises the exact picker/magnifier/ruler UI and algorithms without requesting desktop capture. Multi-monitor and mixed-scale release testing is still recommended on both X11 and Wayland.

License and attribution

PixelKit is MIT licensed. See NOTICE for PowerToys attribution and trademark clarification. Third-party Rust dependencies retain their respective licenses; cargo deny/distribution tooling can generate the final dependency license inventory for a release.