- Tab Color Underscoring active/read/unread (Fx3.6 )

Colors the
borders of a tab with RED for active tab, BLUE for a normal tab, GREEN for a still unread tab, MAGENTA(FUCHSIA) for loading/reloading tab. In other words distinguishes tabs as active tab, viewed tab, unviewed tab. Does not affect the background color of a tab so that color usage of "Perma Tabs" ("Perma Tabs Mod"), and/or "Multiple Tab Handler" extensions will prevail. Bottom border color will show up even if tabs on the tabs bar have been squeezed down so much that only the favicon can be seen.

The style for Firefox 29 (Fx29, Australis) is Tab Color Underscoring active/read/unread (Fx29) (101570), you will still need the TabVisted extension in Fx29, described below.

You must install the TabVisited extension to use this style (see below).

To use this style, install Firefox and Stylish. If you already have Stylish, make sure this site is allowed to run JavaScript.

Tab Color Underscoring active/read/unread (Fx3.6 )
Author David McRitchie
License CC-NC-SA
Created Jan 31, 2010
Updated Apr 11, 2011
Installs (this week) 2
Installs (total) 2,404
Show CSS


This Notes area has separate vertical scrolling, such scrolling may be invisible until you move cursor over them. Having to scroll is bad design and I have nothing to with Firefox, Styling documentation design, or some extension that makes this happen beginning somewhere before Firefox 29. If you are using Firefox 29 and above you may need this documentation, but this would be the wrong style.

Tab Color Underscoring active/read/unread for Fx4 - Tab Color Underscoring active/read/unread for Fx4 is not needed for 4.0 this one now works on both 3.6 through at least 6.0

This style has been rewritten for Firefox 3.6 thru Firefox 28 but otherwise same as Tab Color Underscoring active/read/unr (pre 3.6) (9023). Firefox 29 and above need to use Tab Color Underscoring active/read/unread (Fx29) (101570)
The reason and suggested code changes can be seen in
Install TabVisited 2.5 to use in Firefox 4.0

Consider this style to be a TEST for now until the supporting code which can be installed from comment 6 of bug 487242 becomes part of Firefox.

If you get the following error for [JavaScript Application]
TypeError: Components,classes[';1)'] is undefined
then you did not install the TabVisited extension in bug 487242#c6

Firefox 4.0 shows tab favicon changes builtin): (CW is clockwise, CCW is counter-clockwise) not an indication of whether page is read or not though.
CCW and gray: we have sent the request and are waiting for the server to respond.
CW and blue: we have started getting data back from the server and are working on rendering the page.


An unread tab is one that has been opened in the background such as with a mouse shortcut, and will also be seen for tabs restored from a terminated session.

When a tab is opened in the background the current tab remains active (Ctrl+Shift+click)
When a tab is opened in the foreground the the new tab becomes active (Ctrl+click).
The mouse shortcuts that I use above are reversed from Firefox's default because I checkmark the option at Tools, Options, Tabs, [x] When I open a link in a new tab, switch to it immediately.

My method of reading most web pages is to stay within the article, opening links in the background at the far right of the tabs bar, when I have finished reading all of the originally selected pages, I start reading the new pages in the same manner, new tabs to the a right after all they are secondary material. I try not to build up layers within a tab, so that I can tell for sure when I am finished with a tab. Especially when reading Blogs where I start with several blogs by opening them from a folder on my bookmarks toolbar.

If "private browsing" for the active tab in particular can be determined might add an dotted black border at top of tab. [Unfortunately Private Browsing is all or nothing it is not per tab].
border-top: dotted 2px #FF6600 !important;

This style can be used together with Tabs Bar Minimal Size (9043) by David McRitchie.
(This style will show magenta underscore while loading, pictures shown are same as used in Tab Color Underscoring active/read/unr (pre 3.6))

Updates to code since 2008-07-24 (base code)
2010-01-31 this new style to work with Firefox 3.6
2010-02-07 color loading/reloading tab
2011-04-11 all borders to work in 4.0, see only bottom in 3.6



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