Ambiance and Radiance are two Gtk themes and they have a version compatible with Xfce/Xubuntu.
Ambiance has dark panel, dark toolbar and dark window title bar, while Radiance displays this elements with light colors.
There are also some color variations for each theme: Blue, Graphite, Green, Orange, Pink, Purple, Red and Yellow.
InstallOpen a terminal window and run:
# Add Ravefinity Project PPA sudo add-apt-repository ppa:ravefinity-project/ppa -y # Update package information and install ambiance and radiance themes sudo apt-get update && sudo apt-get install ambiance-xfce-lxde radiance-xfce-lxde # Install other colors variations (blue, green, purple, ...): sudo apt-get install ambiance-colors-xfce-lxde radiance-colors-xfce-lxde