Generally speaking, you can modify Firefox's interface using custom style rules, or you can use a more purpose-built add-on.

Are you already using a "full" theme that lets you modify the toolbars? I'm not sure of the best approach in that case -- what is most compatible, but you could try this one:

https://addons.mozilla.org/firefox/addon/theme-font-size-changer/

See if this can help you

NoSquint {web link} NoSquint allows you to adjust the text-only and full-page (both text and images) zoom levels as well as color settings both globally (for all sites) and per site.

You already have the Stylish extension, so you can try to use the DOM Inspector to find the ID of items where you want to change the font color (text color) if you do not want to change it for the entire user interface.

• DOM Inspector: https://addons.mozilla.org/firefox/addon/dom-inspector-6622/

• https://developer.mozilla.org/DOM_Inspector
• https://developer.mozilla.org/Introduction_to_DOM_Inspector

The DOM Inspector (DOMi) has a menu item (Edit > Select Element By Click) and a toolbar button "Find a node to inspect by clicking on it" (left icon on the toolbar in the DOMi).

• open the browser window in the DOMi (File > Inspect Chrome Document) and choose the first entry from the drop-down list.
• click the "Find a node to inspect by clicking on it" button and use the keyboard (Alt Tab) or the Task bar to go back to the browser window (do not click in the browser window other than the title bar).
• click that element with the mouse and keep the button pressed until you see a red border to indicate that the DOMi has located that element in the DOM tree.

@jscher2000, @FredMcD: I already have enough addons installed, and I'm pretty happy with the interface overall. Thank you for your suggestions, though.

@cor-el: Will this addon require me to keep it installed in order to keep the changes active? That is, if I were to change that font colour, and then uninstall it, would the change(s) revert?

You can use the userChrome.css file in the chrome folder instead if you do not want to depend on Stylish. I always use userChrome.css with in most cases only @import rules that can easily be adapted for various Firefox versions.

• @import url("xxxxx.css");

The customization files userChrome.css (user interface) and userContent.css (websites) are located in the chrome folder in the Firefox profile folder.

• http://kb.mozillazine.org/Editing_configuration

I was wondering, but didn't ask before, whether it remains green if you move it to another bar. In other words, is there something special about that top title bar/menu bar area that is affecting the font color.

@cor-el: I'm not very experienced in this kind of deep editing... What exactly would this do? :/

@jscher2000: Ah, good point. I didn't think of that. Hang on, I'll check...

• goes to check*

Ah, wow. Okay, problem solved, everybody! ^^" Turns out it was a combination of the complete theme I had installed and the toolbar. With the theme installed, if I moved it to another toolbar, it would change back to its default colour, which was...dark grey? Whatever colour that is... But if I removed the theme althogether, it would revert regardless of whether I moved it.

Hehe... Yeah...so... Er... Sorry if I wasted any of your time... :/

Well, if you decide you love the theme and the zoom controls in the top bar, then cor-el's method is still available.

Well, thank you. That would seem a good thing to me. ^_^

And thank you as well, cor-el!