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Color Blindness Simulator

Explore how a palette or image changes under a published color vision deficiency model. Compare your original with a simulation, then use the result to identify places where color needs support from labels or patterns.

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Compare your colors

Machado model, tabulated severity 1.0, applied to linearized sRGB then clipped to the display gamut. The tritan model is a shift-based approximation, not a faithful model of complete tritanopia.

Simulated palette

#a0913e · #b5a766 · #007df4 · #d0b914 · #1980f3

PNG, JPG, WebP, GIF, AVIF, BMP; up to 64 million source pixels. Animated images use a still frame.

Design review notes

A simulation can reveal color pairs that become harder to distinguish. It does not reproduce an individual’s experience or diagnose vision. Use labels, patterns, and shapes alongside color; verify text contrast separately.

Image previews and PNG downloads are scaled down to at most 1,200 pixels on the longest edge. Transparent pixels retain their alpha; inspect your image on the intended final background.

Numerical data attribution and BSD license
Copyright 2013 Colour Developers

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE

Original image

Choose an image or try the example above.

Deuteranopia · red/green

Image processing and generated artwork stay in your browser. Files are not uploaded by this tool.

GET STARTED

How to use the Color Blindness Simulator

  1. 01

    Choose protanopia, deuteranopia, or the explicitly labeled severe tritan approximation.

  2. 02

    Edit the five palette swatches, or upload a local raster image to see an original-and-simulated comparison.

  3. 03

    Inspect colors that become harder to distinguish. Download the simulated image if you need a design review artifact.

Examples

Chart legend review

Set the palette to the five colors in your chart and compare the transformed swatches. If two series become similar, add direct labels or distinct line styles rather than relying only on hue.

Image-based UI review

Upload a screenshot with status badges and compare it under both red/green simulations. Check that words or icons still distinguish success, warning, and error states.

Published model and color processing

The numerical tables come from the Colour project’s Machado dataset, based on Machado, Oliveira, and Fernandes (2009), with the tabulated severity fixed at 1.0. The implementation decodes sRGB channels into linear light, applies the 3 × 3 matrix, clips out-of-gamut results, and re-encodes sRGB. Alpha is preserved. The source data attribution and full BSD notice are available in the tool.

What the preview can and cannot establish

A simulation is a design aid, not a diagnosis or a reproduction of one person’s vision. Displays, adaptation, the scene, and individual differences affect perception. The tritan table uses a shift-based approximation; the model’s own documentation cautions against treating it as a faithful model of complete tritanopia. Review contrast separately and involve people with relevant lived experience when evaluating important interfaces.

What to know

  • The simulated image is limited to a 1,200 pixel longest edge.
  • Transparent artwork should be checked on its intended final background. This is not a clinical or individual vision assessment.

Common questions

Does this certify accessibility?

No. The preview does not assess keyboard access, text contrast compliance, readable labels, or the many other parts of an accessible design.

Can I simulate partial severity?

This implementation offers only the documented tabulated 1.0 endpoints. It does not label a simple blend with the original as a validated severity model.

Why is the download smaller than my original?

Images are reduced to at most 1,200 pixels on the longest edge before processing. The downloaded PNG uses that preview resolution to keep local memory and computation bounded.

Sources & references