What's the Firefox add-on to dim the whole page of a site?

I upgraded my PC and foolishly thought I knew all the add-ons that I used so wouldn't need to write them down!

Basically I had an add-on that I thought was called something like 'lights out' or similar.

All it did was enable you to have a little button which changed the CSS of websites with the click of a button, so that white backgrounds became grey and made the whole page dimmer.

It had various different built in themes to choose from, and there was an option called 'stay in the dark' which meant whatever page was loaded in the tab you were in would continue to use one of the anti-glare/brightness themes for night time reading etc.

It was a great little add on, but I can't seem to find it anywhere. The icon was a simple little light bulb with a drop down menu to select different themes.

Can anyone help me find the add on please!?

Do you mean Blackout?

If you are browsing in a dark environment, then it is very bad for your eyes to read pages with white background. This plugin helps you by turning the webpage to a dark color scheme.

• There are some predefined color schemes built in, and you can also configure your color preferenes.
• The "Stay in the dark" function enables you to automatically darken the page when you click on a link and the page loads.
• Links and headers gets different color then text.

I've been looking for an add-on to do this consistently without (for the most part) severely dulling the color of pictures, inverting the black hues of webpages to stark whites and transforming bright colors to darker ones.

After a bit of fiddling, I've got the settings on this one dialed in to do all of that to a surprisingly high degree using Colorific [ https://addons.mozilla.org/en-US/firefox/addon/colorific-1/ ]

Chrome, after almost a decade, still flashes the base background color of white when loading a webpage, but in Firefox this problem can be avoided. I've installed "FT DeepDark" for my theme. This theme addresses the base background color that gets displayed while the browser receives the intended color from the website. Colorific addresses everything else!

Blackout didn't work well at all for me. If you have color Accessibility issues or eye strain, take a bit to try Colorific. Evidently you can share your settings with others.

Here's the settings I settled on in Colorific, if you'd like to try it yourself:

0,255,0,255,143,55,-47,119,1,pmfhrbs;0,255,0,255,-26,217,0,255,0,ivtg;0,255,0,255,196,199,0,255,0,clo

The backgrounds were the toughest part to get right:

You can tint all webpages yellow, for example, or change all text to a high contrast. I've been looking because I like to keep everything dark; I prefer the white on black look, but this keeps the subtle color details that make pages look sharp. If you want all sites to automatically have the theming applied, make sure the "plus inside a square" icon is Off under the General Options, making the white list obsolete if done right. The main things I changed were the Lightness Slider for the Text (made them lighter) & Backgrounds (made them darker), and I kept the Image elements mostly untouched.