Setando o tema Ambience com transparência total no ubuntu

Source: http://www.techsupportalert.com/content/ubuntu-tips-and-tricks.htm

Set Full Transparent Panel

When you set the panel to be transparent in the default Ambiance theme in Ubuntu 10.04, you will find that some panel items' backgrounds are not transparent, but you can make them transparent and consistent with others, following these steps:

1. Go to Applications (or Main Menu) > Accessories > Terminal.
2. Enter cp -R /usr/share/themes/Ambiance ~/.themes/
3. Enter gedit ~/.themes/Ambiance/gtk-2.0/gtkrc to open Ambiance's ftkrc file with gedit.
4. Search for this line bg_pixmap[NORMAL] = "panel_bg.png"
5. Comment out the line by placing a # at the beginning of the line, like this: # bg_pixmap[NORMAL] = "panel_bg.png"
6. Save the gtkrc file.
7. Go to System > Preferences > Appearance, switch to the other theme and then back to the Ambiance theme.

Note: If you'd like to change to the Radiance theme, replace Ambiance with Radiance in the above command lines, but you'd like to change to the New Wave theme, then enter cp -R /usr/share/themes/"New Wave" ~/.themes/ in step 2, enter gedit ~/.themes/"New Wave"/gtk-2.0/gtkrc in step 3, search for and comment out this line bg_pixmap[NORMAL] = "Images/Panel/PanelBarLong.png" in steps 4 and 5 respectively.

Para controlar a transparência das bordas das janelas faça:



Veja também: http://www.techandlife.com/2010/05/useful-links-ubuntu-10-04-post-installation-tips/