Changing Facebook Theme

Go to https://addons.mozilla.org/en-US/firefox/addon/3120 and install the Firefox add-on named "Boost for Facebook" (now 9.0.18 version) — it works also in Firefox 3-current.
restart Firefox.
CLICK your new extensions icon in the corner Firefox. (right corner)


Now you will see a new window.
Click DISPLAY tab.
Check skin top menu bar
Check apply light color to Posts
Choose preloaded skins and press the drop down button to decide which ones do you prefer !!
Click OK.

Restart Firefox & open Facebook .It's complete.