Seting Color for Holiday ( in delphi1's calendar )


I am learning to write a progarm for myself which is a small memo
which include a calendar inside it. I am using delphi's calender
component, but I do not know how to change some of the day's color,
for example hoilday like X'mas using red color, examination using
green color on some day in the calendar. Do you know how can I do
that? Please tell me. Thank you.