Fixes #4265: overwrite custom colors and backgrounds in articles in dark mode
Fixes #4265: overwrite custom colors and backgrounds in articles in dark mode

zammad/zammad,monotek/zammad,zammad/zammad,zammad/zammad,zammad/zammad,zammad/zammad,zammad/zammad,monotek/zammad,monotek/zammad,monotek/zammad,monotek/zammad,monotek/zammad