I finally managed to fix the color issues on Openoffice. Indeed, when messing around with the gtk colors, you will notice that openoffice doesnt like it at all. So here is the fix :
Write this in a terminal:sudo gedit /usr/lib/openoffice/program/soffice
Then insert a new first line and write this on it:export GTK2_RC_FILES=/usr/share/themes/Clearlooks/gtk-2.0/gtkrc
Then save it and close gedit.
Make sure that every OpenOffice-application is shut down. Then try to start a new one to see if it works.
Note that Clearlooks can be replaced by any other theme. This will force openoffice to use that theme and keep the colors from being corrupted by your current gtk colors.