How to use Color Blindness Simulator
- Enter supported palette colors.
- Choose a named full-deficiency simulation.
- Compare original and simulated colors and review close pairs.
Example: Color Blindness Simulator
A palette containing black, white and two colored swatches.
Options
- Simulation type
- The selected model approximates full-severity appearance. It is a comparison aid, not a prediction of any particular person’s vision.
- Pair review distance
- This cutoff uses distance in simulated linear RGB multiplied by 100. A flagged pair deserves review, but the cutoff is not a WCAG contrast or accessibility pass.
Supported inputs and limits
Where your input is processed
This tool processes your input in this browser. Your text and files are not uploaded to UseFreeTools. Check this tool's limits for anything it may save on your device.
Preserve information beyond color
If two labels become hard to distinguish, add text, shape or position cues to the actual design. Check text/background contrast separately from this palette comparison. The report describes the entered colors under a model, not every screenshot, visual condition or degree of color-vision difference.
Questions about Color Blindness Simulator
Does the preview diagnose color vision?
No. It is an approximation for design review, not a test of a person’s vision.
Do close-color flags measure WCAG contrast?
No. Use the site’s contrast tool for its separate supported contrast calculation.
Why can the result differ from another simulator?
Models, gamut handling, display calibration and the simulated condition can differ.