When you add calendar items and set the Show As availability to “Out of Office” the color is unexpectedly changed which may make it difficult to distinguish between the other types of availability. The expected color is purple, but it is changed to light blue or another light color depending on the color of your calendar. Before: Version 2402 After: Version 2403
Dark mode changes the default bright background color in Outlook.com and Outlook on the web to a darker color, which is easier on the eyes in low-light environments or if you prefer less bright interfaces.