Understanding Calendar Shading

Appointments on your calendar appear in different shades, depending on how the appointment is shown:

Busy: The appointment displays as gray.
Free: The appointment displays as white.
Out of the Office: The appointment displays as dark gray.
Tentative: The appointment displays as gray with white and gray stripes on the side.

To change an appointment’s Show Appointment As status:

Open the appointment, then click Busy, Free, Tentative, Out of the Office, or Tentative from the Show As drop-down menu.