Aging Tabs
Makes unused tabs fade with age and highlights the selected tab.This extension is intended to be used along with the Firefox 2 default theme on Linux or Windows. Other themes are potentially incompatible, if they use opaque tab images or alter the DOM structure inappropriately.List of compatible themes available at http://en.design-noir.de/mozilla/aging-tabs/. Also feel free to make suggestions there (especially if you expect an answer; I can't respond to the comments made here).
Supported
versions: Firefox 2.0 - 3.0a2 ALL
Notes / Comments: hidden pref for delay after switching tabs: browser.tabs.agingDelay
Categories: Tabbed Browsing

Different Settings:

Preferences:
