There is no setting for this within Eclipse that works for all cases. You will have to set this on an OS level as recommended by several other answers and it will vary depending on your OS and desktop environment.
However, on some versions of Ubuntu (specifically 14.04), none of the methods mentioned in the answers so far work correctly.
In that case, refer to this this answer on AskUbuntu, which lists the files that need to be edited in order to change the tooltip foreground/background colors to black and white OS wide for the built-in themes. In addition to those, I had to edit one more file (gtk-main.css
).
The files that need to be edited are:
/usr/share/themes/Ambiance/gtk-3.0/settings.ini
/usr/share/themes/Ambiance/gtk-3.0/gtk.css
/usr/share/themes/Ambiance/gtk-3.0/gtk-main.css
/usr/share/themes/Ambiance/gtk-2.0/gtkrc
Set all instances of tooltip bg colors to #ffffff
(white) and tooltip bg colors to #000000
or any other color combination you like. If you use the Radiance (light) theme instead of the default Ambiance theme edit the files in the corresponding Radiance folder.