My colleague delegated to me his calendar and it's working fine. Is it possible not to display my own calendar and to display only the calendar of my colleague in my outlook? Thank you

Click on Calendar so that your outlook switches to Calendar view. Now, select your calendar and your colleagues and the deselect the check box against your calendar. That should display only your colleagues calendar. However, you cannot completely remove your calendar from your outlook as it is one of the default folders.

Were you able to setup to see only your colleagues calendar in outlook?