I just edited the Harmattan Icon pack (by cloud596) and made it compatible with this theme (mostly white themes).

You can download it from Here and just extract the contents to a file and move it (harmattan-icon-pack folder) to
[usr/share/icons] - (via winssh) and overwrite all files.

Note: all credit goes to cloud596, i just edited some of the files and increased the contrast level.

Edit: link fixed