These icons are a mod of the package from rowancompsciguy's Pidgin Tray Icons v0.3 pack (http://gnome-look.org/content/show.php/Pidgin+Tray+Icons?content=119879). These are great looking Pidgin icons, but were not the correct brightness level or color. I modified the color, brightness, contrast to make them more like the monochrome themed icons in the Ubuntu Ambiance theme.
This icon pack folder structure is set up to replace the "hicolor" folder located at /usr/share/pixmaps/pidgin/tray. To copy the files, first extract, then copy with sudo and overwrite originals or replace after backing originals up.