Leo Lannacone has designed the perfect Gwibber theme to compliment the GTK Dust theme.
You can download the code using bazaar*: -
bzr branch lp:~l3on/gwibber/dust-theme
To install it, put it into the following folder:
now just open Gwibber and select the new theme from the preferences dialog.
I love Gwibber. I really do. So having it match my desktop theme is awesome! Props to Leo!
*To install bazaar use:
sudo apt-get install bazaar