Display Color

Display Color is a small GTK4 app for Wayland that provides quick per-output color tuning (RGB channel reduction, contrast, and gamma).

Tested on:

• GNOME on Wayland (Mutter fallback path)
• KDE Plasma on Wayland (Wayland gamma and ICC fallback path)

This tool is meant for fast correction of poor laptop panels when you do not need full color calibration. It is similar in spirit to Intel/AMD display color controls on Windows (quick RGB/contrast/gamma adjustments), but built specifically for Linux Wayland sessions.

Requirements

• Linux Wayland session (GNOME or KDE Plasma)
• Python 3.10+
• GTK4 + PyGObject (system packages)
• Python packages: pywayland, dbus-next

Install system packages first:

• Debian/Ubuntu:
  • sudo apt install python3 python3-pip python3-gi gir1.2-gtk-4.0
• Fedora:
  • sudo dnf install python3 python3-pip python3-gobject gtk4
• Arch:
  • sudo pacman -S python python-pip python-gobject gtk4

Optional fallback tools (recommended):

• KDE fallback: kscreen-doctor (usually from kscreen package)
• GNOME fallback uses Mutter D-Bus (SetCrtcGamma) and does not require extra CLI tools

Install Python dependencies:

python3 -m pip install --user -e .

Run

python3 -m linux_rgb_monitor

or after install:

linux-rgb-monitor

Notes

• Wayland-first design: this app targets Wayland compositors.
• Uses zwlr_gamma_control_manager_v1 when available.
• Falls back to Mutter SetCrtcGamma on GNOME and KScreen ICC profile apply on KDE when needed.
• RGB sliders use integer values in the safe range -50..0 (0 = default/no RGB reduction).

Config

State is stored in:

~/.config/linux-rgb-monitor/config.json

Troubleshooting

• Make sure you are running a Wayland session (not X11).
• If no outputs are controllable, check that your compositor exposes gamma control.
• If warnings indicate control conflict, disable other color tools and retry.