This tool simulates how webpages look for people with:
Therefore the extension changes the DOM of your HTML document, the stylesheets and the images.
It replaces all original colors with the color that a colorblind person would see.
All content that is drawn by plugins (flash, videos, ...) stays unchanged.
Please leave a report, I need your experiences to make this software better.Limitations
- In contrast to older version html background attribute is not supported
- Plugin stuff still not supported
- Lots of ways that bring color to your document not supported
- No SVG support
- Gradients and Alpha is hard to cover correctly
- Processing is slow and blocks the browser. But this is not an Extension that is used the whole day so we have to live with it
That means if you use anything special that is not supported you could use a fallback method by processing a screenshot of your website.
The advantage of using the DOM way is that you have also support for css pseudo classes for example :hover.Accuracy
First of all, I am aware that this implementation does not match 1 to 1 with vischeck or other tools.
The algorithm is based on the papers:
- Computerized simulation of color appearance
- Corresponding-pair procedure: a new approach to simulation of dichromatic color perception
- Digital Video Colourmaps for Checking the Legibility of Displays by Dichromats
I am really interested if you find bugs or wrong assumptions in the implementation of that algorithm. The code is hosted here https://github.com/ISO50/dichromat-simulation
. You can contact me on my github account.Changelog
- Version 5.0.6 fixes the Extension to work with newer Firefox Versions as the API has changed a lot.