Colouring appointments in Outlook 2000?

Is it possible to add a colour to an appointment based on it’s category? I used to be able to do this many moons ago in Lotus Smartsuite, but can’t find a way in Outlook. Even if it means a 3rd party solution, I’d like to be able to do it – we have 25 users who access a departmental calendar, and it would make life so much easier.

Many Thanks