The standard LibreOffice skin in Ubuntu 14.04 and 14.10 looks rather simple.
There is a fine alternative icon theme/skin which can be installed easily. Just execute this command in your terminal application.
sudo apt-get install libreoffice-style-sifr
- Re-/Start LibreOffice.
- In LibreOffice visit the menu Tools > Options > LibreOffice > View and set “Icon size and style” to Automatic + Sifr