Do ubuntu chơi bản murrine gtk engines tải từ git về chứ không phải bản release như gentoo hiện tại nên theme không dùng được.
Giải pháp: Mở file gtkrc của ambiance (và radiance chắc cũng tương tự) comment out các dòng nào bị báo lỗi
pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:111: error: unexpected identifier `border_shades', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:129: error: unexpected identifier `prelight_shade', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:135: error: unexpected identifier `separatorstyle', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:136: error: unexpected identifier `shadow_shades', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:138: error: unexpected identifier `spinbuttonstyle', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:140: error: unexpected identifier `textstyle', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:142: error: unexpected identifier `trough_shades', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:203: error: unexpected identifier `border_shades', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:254: error: unexpected identifier `border_colors', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:338: error: unexpected identifier `border_shades', expected character `}' pntruongan@localhost ~ $ gedit /home/pntruongan/.themes/Ambiance/gtk-2.0/gtkrc:407: error: unexpected identifier `border_shades', expected character `}' pntruongan@localhost ~ $ gedit