I have the British English dictionary set as the default under my Identity->Advanced tab (only American English and British English are given as options, and my OpenSUSE Leap 15.1 base system is set to British English (United Kingdom)). If I click on "Spelling..." when composing a new email my language is also set to British English. However, the spellchecker will underline in red "colour" but not "color". I would expect the opposite. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Plasma Version: 5.17.90 KDE Frameworks Version: 5.66.0 Qt Version: 5.14.1