Version: 3.2.1 (using 4.2.1 (KDE 4.2.1) "release 106", KDE:KDE4:Factory:Desktop / openSUSE_11.1) Compiler: gcc OS: Linux (x86_64) release 2.6.27.19-3.2-default In "settings" / "configure kate" / "editor component" / "fonts & colors" / "highlighting text styles", right-clicking a line reveals "unset background color". It changes the UI component (a button) to correctly say "None set", but this doesn't change the effect in the document ever, and is forgotten when the settings dialog is relaunched.
*** This bug has been marked as a duplicate of bug 242576 ***