At some point (which I unfortunately didn't note down precisely, but is reasonable to believe that it was after an apt-get (dist-)upgrade operation) meld's background highlighting stopped being displayed correctly.
In the following screenshot you can see that the light blue highlighting is missing from the two text panels:
Compare e.g. with http://meldmerge.org/ screenshot:
I tried to hunt for the problem by reading about Gtk Css (which meld is apparently using) and went as far as checking that my /usr/share/meld/meld.css has the right contents, but I have no clue what to do next.
I am running Debian Jessie, GNOME and $ meld --version returns meld 3.12.0.
I cannot find any menu or command line option to reach a "Preferences" menu in the version that I am using.
