Why does my Xubuntu LibreOffice look ugly?

By investigating with Synaptic and trial & error method I came up with the solution:

sudo apt-get install libreoffice-style-tango libreoffice-gtk libreoffice-gtk3

I have no idea why these packages were missing. I hope this helps someone.

sudo apt-get install libreoffice-gtk

Also upper command line works for lubuntu (LXDE). For example with flat gtk theme 'victory' and 'papirus' icons LibreOffice looks great.