RGBlind for Firefox

RGBlind is an easy-to-use browser extension that simulates color blindness during web navigation sessions. It applies filters to webpages opened in Firefox to demonstrate how they are seen by people with protanopia and deuteranopia. You can also check out RGBlind for Chrome and RGBlind for Opera.

This type of software comes in handy to web developers and designers who wish to make their websites as accessible as possible by finding out how color blind users are experiencing the pages. This way, readability can be improved.

The browser addon can be easily downloaded and installed from Mozilla. It doesn't require browser restart and can be activated from an icon next to the address bar.

You can quickly switch to protanopia or deuteranopia mode since the filter is applied immediately, without having to click any other buttons. Changes can be undone by switching back to normal vision mode.

Worth noting is that the filter only applies to the current page, so it cannot transform pages from all opened tabs. In fact, the filter from the current tab is disabled as soon as you navigate to a new page. It would've been useful if the developer implemented options for keeping the filter active for the current tab even while opening new pages, as well as for all opened tabs.

In addition to Mozilla Firefox, RGBlind can be integrated with Google Chrome and Opera. The app is free and open-source. It's also available as an online color blindness simulator for URLs as well as a web toolkit (CSS, JavaScript, SVG). It doesn't work with Microsoft Edge or Internet Explorer.

We haven't experienced any compatibility problems with the latest Firefox version in our tests. The browser addon applied modifications quickly without causing page rendering issues.

Taking everything into account, RGBlind may not have many options or any configuration settings, but it comes in handy for web designers interested in improving readability on their websites by finding out how pages are seen by colorblind people.