The Greybird theme for GTK2/3 and xfwm4/emerald/metacity/mutter started out on the basis of Bluebird, but aims at reworking the pale blue color to a modern and vibrant blue that will be more pleasant to look at in everyday use.
Greybird is a lot more modern and feature-rich than Bluebird was in Xubuntu Maverick. Amongst other things it sports
- Full GTK3 support
- Native Chrome/ium theming (for >= v.9.0.597)
- Application specific theming for Thunar and xfce4-terminal
- Other xfce elements like panel and the application switcher
- Panel plugins, including special theming support for Ubuntu’s indicators
- Firefox and LibreOffice support
- Compiz/Gnome support (emerald, metacity and mutter themes)
- High accessibility and readability
For Xubuntu Oneiric Ocelot (11.10) we added support for both emerald and metacity to serve those who like the *zing* and *bling* of compiz in xfce. We also added full support for GTK3 and used the heir of the legendary murrine-engine to closely match the GTK2 theme: the unico-engine (developed by Canonical’s Andrea Cimitan).
Later, we dropped the unico-engine in favour of the built-in theme engine in GTK3, trying to make the both GTK2 and GTK3 themes resemble each other as closely as possible. The theme has gotten a major overhaul with brighter and more modern colors. The latest version also supports Client Side Decorations. A mutter theme is also provided for anti-aliased window corners if you want to use another window manager such as mutter, gala or muffin. Support for granite-widgets was also added, improving the way elementary apps look with Greybird.
One thing we plan to work on is more application specific theming, e.g. Ristretto (image viewer) and Parole (media player). Another specifically supported application area might be our gmusicbrowser layouts. Our initial tests for this were promising, but GTK3 theming just ate up too much time in the Oneiric release cycle so this’ll have to stay on the todo-list for now.