Prerequisites WAVE or axe browser extension. Setup Log in as an admin Create a course C1 with groups Assign a user m1 as a manager in the system context. Enrol m1 to C1 as a manager Log in as m1. Go to the calendar. Create an event for each type on the same date: Site, Category, Course, Group, and User. Test - Monthly view Make sure the calendar's on the monthly view. Check the indicators of the events in the main monthly view of the calendar. Confirm that the events indicators now have a 2px border that has good contrast against the white table cell background. Run the WAVE or axe tool. Confirm that you don't get any colour contrast errors related to the calendar events in the main calendar. the " Events key " section. the mini calendars in the " Monthly view " section. Test - Day view Click on the date link containing these events to open the day view of the calendar. Run the WAVE or axe tool. Confirm that you don't get any colour contrast errors related to the list of events in the day view. the " Events key " section. the mini calendars in the " Monthly view " section.