Eclipse javadoc background color is black

Question

Window > Preferences > General > Appearance > Colors And Fonts > Java
> Javadoc View Background  

You need to change the 'Tooltip' color in Ubuntu at the OS level.

None of the answers here worked for me (I have Eclipse Mars and Ubuntu 14.04). I had to edit /usr/share/themes/Ambiance/gtk-3.0/gtk-main.css. I've changed tooltip_bg_color to #f5f5bf# and tooltip_fg_color to #000000. After restarting eclipse, the change took effect.

As a KDE user you have to change the tooltip background color with systemssttings.
Navigate to

Application Apperearence -> Colors -> Colors

and adjust the Tooltip Background and Tooltip Text colors.

On ubuntu 12.10 (quantal) you can use the following two commands:

#foreground white => black
sudo sed -i s/tooltip_fg_color:#ffffff/tooltip_fg_color:#000000/g  /usr/share/themes/Ambiance/gtk-3.0/settings.ini /usr/share/themes/Ambiance/gtk-3.0/gtk.css /usr/share/themes/Ambiance/gtk-2.0/gtkrc
#background black => yellow
sudo sed -i s/tooltip_bg_color:#000000/tooltip_bg_color:#f5f5b5/g  /usr/share/themes/Ambiance/gtk-3.0/settings.ini /usr/share/themes/Ambiance/gtk-3.0/gtk.css /usr/share/themes/Ambiance/gtk-2.0/gtkrc

(Thanks to the other answers and this that helped me to figure this out)