This issue (which did not occur with a fresh install of 16.04) appears to be related to the contents of file: /usr/share/themes/Ambiance/gtk-2.0/gtkrc
At line 346 (at present) there is the following: style "menu" = "dark" { Changing it to: style "menu" { ... resolves this particular issue, however I'm not sure what side- effects that would have. In the original release the line was like that in the first place, so it would have been changed for a reason. Screenshots of "before" and "after" that change can be seen here: https://askubuntu.com/a/1014016/425017 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1750973 Title: Program sub menus dark gray on black, thus illegible To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1750973/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs