I think I read somewhere that some adjustment was possible, making LibreOffice fit in reasonably well with the rest of the system, but I can't find it anymore.
The folks from Xubuntu are currently working on an elementary icon theme for LibreOffice in Github
I'd suggest the sifr theme. Use this command:
sudo apt-get install libreoffice-gnome libreoffice-gtk libreoffice-style-sifr libreoffice-gtk3
However, a lot of people suggest customising the crystal theme.
sudo apt-get install libreoffice-style-crystal
Type ‘Y’, and press enter to complete.
Now, download the Faenza theme here.
Now, after downloading Faenza theme (Don’t worry about it being called images_crystal.zip – it’s the Faenza package, but it’s just been renamed to save you having to do so) you will need to obtain ‘Root Access‘ to be able to modify themes. So, into a Terminal copy and paste, or type out the following:
sudo -i pantheon-files /usr/share/libreoffice/share/config
Next, remove, or rename the
images_crystal.zipfor in case anything goes wrong. I renamed it to
images_crystal_old.zip. Doing this ensures you have a fall-back should anything go wrong.
Now, simply transfer your new
images_crystal.zipover to your Files window, and all being well, it should have appeared.
Now, fire-up LibreOffice, and go to
Tools — Options — View, and change the theme to Crystal.