This is done by having multiple calendars ... each one can be a different color. I have 4; My kids events (Green), My events (Red), My wife's events (Blue), and out business events (Brown). When I create an event, I have to specify which calendar I am making it for, it that gives it the correct color. It also works well if you want to share one of the calendars. For instance, my parents and my wife's parents have a web link to out kids calendar. They can view when my son has hockey or when my daughter has dance, as well as any school functions we throw on it ... but they cannot see the event on my other calendars. Our clients can see the events on our business calendar, but none of the three personal calendars.