OpenOffice.org suffers from a long-standing bug where dark desktop themes cause it to drop into a high contrast "accessibility" mode, thus losing all colours. The following commands will give a work-around:

cd /usr/lib/openoffice/program

sudo mv soffice.bin soffice2.bin

sudo mv soffice soffice2

sudo gedit soffice

Enter the following text into the editor and save it:

#!/bin/sh
env GTK2_RC_FILES=/usr/share/themes/Clearlooks/gtk-2.0/gtkrc /usr/lib/openoffice/program/soffice2 "$@"

Then execute sudo chmod +x soffice