I don't know if this is the default Shiira theme or not but I saw a screenshot here: http://hmdt-web.net/shiira/screenshot/en
If you scroll down slightly, there is a Shiira window with a brushed background and purple, red, and green buttons. It seems to be the "Colors 2" theme available @ http://hmdt-web.net/shiira/icons/en .
It looks nice, it would be great if someone was able to make this skin for Firefox.
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