Jaden Peterson

You're going to want to start [here](https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox). Then once you've enabled the Browser Toolbox you can enter it as described in the article and start modifying/testing custom CSS. You can...

Firefox 54.0 Stable on Arch doesn't work either.

Firefox Photon with Arc Colors looks pretty nice, here's what I've been using, add it to prefs.js: ` user_pref("lightweightThemes.usedThemes", "[{\"id\":\"849160\",\"name\":\"Arc Dark Lightweight\",\"headerURL\":\"https://addons.cdn.mozilla.net/user-media/addons/849160/header.png?1504072638\",\"footerURL\":\"https://addons.cdn.mozilla.net/user-media/addons/849160/footer.png?1504072638\",\"textcolor\":\"#ffffff\",\"accentcolor\":\"#82858b\",\"iconURL\":\"https://addons.cdn.mozilla.net/user-media/addons/849160/icon.png?1504072638\",\"previewURL\":\"https://addons.cdn.mozilla.net/user-media/addons/849160/preview.png?1504072638\",\"author\":\"Jaden Peterson\",\"description\":\"Lightweight theme that integrates with the title-bar of...

No they flagged it as too similar to another even though the colors were quite different :/

I think it was the first, though it won't show me anymore. The colors look similar but different when you apply the real theme. Which is exactly why I created...

Can confirm.

Or, if you are using the Arc or Arc-Darker Firefox theme, just use `GTK_THEME=Arc:light firefox` so it can integrate better.

Also, the refresh button isn't working

Yeah

What is the output of `lsb_release -a`?