What do the colors in the calendar mean?

You will see a number of boxes separated by days and hours in your Meeting Calendar. Every color here has a meaning:
Grey: It shows meals, coffee breaks, seminers and other event times. These fields are closed to all participants, and no appointment can be made.
Light green: Shows the appointment slots you have confirmed.
Dark green: Shows your approved appointment requests.
Blue: It shows pending appointment requests that requested from you. 
Yellow: It shows your pending appointment requests.
White: Empty spaces without any events or appointments.
#: Shows meeting information.