This is the app you are looking for.

At the beginning, I got a problem with the add-on. But Alexander took the time to fix it. It is really nice to know that he is there to help you in case something go wrong. I totally recommend the add-on.

I love this app with core of my heart. I really appreciate the developer. It gives me the nostalgic feeling of working on a balck and white monitor. The developer has kept this app free this is also a great thing of appreciaton and applaud.

Dear Developer this is for you: CLAP! CLAP! CLAP! CLAP!

Une extension à avoir absolument, elle fatigue moins les yeux tout en permettant de faire des toutes petites économies d'énergie. Un must have

Flashes, flashes ... If you use a lot of tabs and often switch different web pages, you will kill your eyes from constant millisecond contrast flashes - black-white, black-white. All other features of this extension are perfect.

Perefect!