DaltonLens aims at simplifying the life of color blind people with utility software and technical blog posts.


DaltonLens for Desktop

Utility for macOS, Windows and Linux. It runs as a tray program, always at your fingertip with a global Ctrl+Alt+Win+Space shortcut. It can then show color information below the pointer, capture a screen area and apply a range of color filters on it. It also has a tool to highlight pixels with similar colors which is especially useful to read color-coded charts and plots.

Online Color Blindness Simulator

An extensive comparison of color blindness simulation methods, right in the browser. Use the predefined images or upload your own. It is based on the careful implementations of DaltonLens-Python. Also check the related Review of Open Source Color Blindness Simulations.


Toolbox for research and development on color vision deficiency algorithms. It includes various implementations of color blindness simulators and tools to generate Ishihara-like plates and visualize confusion lines. It is used to create the technical posts as Jupyter notebooks and tries to match the color perception theory as accurately as possible.


Single-file, public domain C library implementing some reference color vision deficiency simulation algorithms. It is meant to be easily copied/adapted.