Ubuntu background color problem

Periodically, when upgrading Ubuntu, I have this background color problem, where for ex my eclipse open popup with a black color background, so I can't read the tooltip content.

I found a solution here.
In my words:

go to /usr/share/themes/Ambiance/gtk-2.0/gtkrc 
and replace #000000 by #f5f5b5

http://askubuntu.com/questions/70599/how-to-change-tooltip-background-color-in-unity

I had to edit these files:

/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

(Addition: for Ubuntu 12.04, it seems youjust have to modify the file: /usr/share/themes/Ambiance/gtk-2.0/gtkrc , replacing the tooltip backround and foreground color, with the #000000 and the #f5f5b5 color, respectively)

You require root privileges to edit the files. Use sudo gedit to edit them.

Search for tooltip in these files and you'll find the color definitions for the foreground and the background. I use #000000 as foreground and #f5f5b5 as background and now the tooltips in all applications are again readable. After changing the color values simply switch to some other theme and then back to Ambiance and the tooltip color is now fixed.