Try The New LibreOffice Flat Icon Set

It looks like LibreOffice will get a new set of flat icons, based on Gnome's symbolic icons. The icon set isn't completed yet, but you can try it already - below you'll find instructions on how to easily try the new icons.

Goran Rakić has posted (thanks!) instructions on how to test the new Libreoffice flat icon set, however, the instructions are not that easy to follow for regular users and the zip in that article is a bit old, so below you'll find easy instructions for how to try the latest flat icons.

Note: the icon theme is work in progress and there are missing icons. For this reason, some of the icons in this set are actually already existing default LibreOffice icons, converted to grayscale, so they integrate better with the new flat icons. The icon theme has been generated from the svg as of 2013-06-13.

Try the new flat icon set for LibreOffice in Ubuntu

1. Install LibreOffice flat icon set

If you're using LibreOffice from the official Ubuntu repositories or PPA:

sudo apt-get install libreoffice-style-crystal
cd /tmp && wget https://github.com/hotice/myfiles/raw/master/images_flat.zip
sudo cp images_flat.zip /usr/share/libreoffice/share/config/images_crystal.zip

The first command above install the LibreOffice Crystal icon set which we'll replace with the new flat icons, the second command downloads the flat icons and the last command replaces the Crystal icons with the new flat icon set.

If you're using the LibreOffice 4.0.x (for older LibreOffice versions you may have to adjust the path for the second command below) build downloaded from its website, use the following commands:

cd /tmp && wget https://github.com/hotice/myfiles/raw/master/images_flat.zip
sudo cp images_flat.zip /opt/libreoffice4.0/share/config/images_crystal.zip

2. Set LibreOffice to use the new flat icons

From the LibreOffice menu select Tools > Options, then under LibreOffice > View > Icon size and style, set the icon theme to "Crystal":

Later on if you want to go back to the original LibreOffice icons, from the same dialog, select "Human" or "Tango" for the icon style.

Other Linux distributions: since I'm not sure about the path used in other Linux distributions, you'll have to manually copy the icons to share/config/ (inside the LibreOffice shared directory) and replace one of the existing icon themes, then set the LibreOffice icon theme to the one you've replaced, from the LibreOffice options dialog (Tools > Options, then under LibreOffice > View > Icon size and style).

If you want to install the icons manually, without using the commands above, you can download the icon set (generated on 2013-06-13) from HERE. 

For how to generate the flat icon set yourself, see Goran's article.

Thanks to Cláudio Novais @ Ubuntued for the tip!