A userChrome theme for Firefox designed to be as faithful to Firefox Photon (specifically Firefox 87) as possible.

There are 2 ways of installing this theme.

• Manually
• As an Extension

Can be installed on all editions of Firefox. There is no auto-updating.

Open about:config and set:

If you're too lazy to copy and paste these about:config preferences, you can visit https://zapsnh.github.io/zcpt-configurator/, enable Include preferences for theme installation, and click Export Options to generate a user.js file that you can put in your profile folder.

Make sure to delete it after you start Firefox so that it doesn't override any changes you make in about:config.

Create security.secure_connection_icon_color_gray as a boolean and set it to true if you don't want the green connection icon.

Download the release for your version:

Static Release (stability):

• Firefox v123 (recommended)
• Firefox 115esr (download the ESR version)

Rolling Release (features and bugfixes):

• Firefox v123
• Firefox Beta/Nightly
• Firefox 115esr

Extract the zip and move zapsCoolPhotonTheme-* to your profile folder which you can find by going to about:support and opening your profile folder/directory.

Rename zapsCoolPhotonTheme-* to chrome

Make sure the directory is like this:

• Profiles > XXXXXXXX.profile > chrome > userChrome.css and others

and not like this:

• Profiles > XXXXXXXX.profile > chrome > zapsCoolPhotonTheme-* > userChrome.css and others

Restart Firefox.

Can only be installed on Firefox Developer Edition, Firefox Nightly, and Firefox ESR. Has auto-updating and a built-in configurator. This version is based on Paxmod.

Open about:config and set:

• extensions.experiments.enabled to true
• xpinstall.signatures.required to false (Why?)

Download the latest version: https://github.com/zapSNH/zcpt-webextension/releases

You're done!

Config options are available at the Wiki.

An interactive configurator is available at https://zapsnh.github.io/zcpt-configurator/. To apply the settings, place the exported user.js file in your profile folder/directory (Profiles > XXXXXXXX.profile), launch Firefox, and then delete it afterwards.

For the WebExtension version, the configurator is can be found in the extension's option page. The settings apply after you click Apply.

Photon Firefox icons are taken from the omni.ja file from Firefox 87. Some other icons are modified/made by me.

Special thanks to:

• black7375's Lepton
• YukisCoffee's Phroton
• The folks over on r/FirefoxCSS
• Mozilla since they made Firefox so customizable (and they made Photon)
• Windows 11 for opening Edge everytime I accidentally press F1 instead of F2 to rename stuff in explorer. I think YOU need to get help Microsoft.