Outlook doesn't support it as an option - but if you use outlook 2007 you
can assign color categories to an all day event that is marked busy.

Signature
Diane Poremsky [MVP - Outlook]
Author, Teach Yourself Outlook 2003 in 24 Hours
Need Help with Common Tasks? http://www.outlook-tips.net/beginner/
Outlook 2007: http://www.slipstick.com/outlook/ol2007/
Outlook Tips by email:
dailytips-subscribe-request@lists.outlooktips.net
Outlook Tips: http://www.outlook-tips.net/
Outlook & Exchange Solutions Center: http://www.slipstick.com
Subscribe to Exchange Messaging Outlook newsletter:
EMO-NEWSLETTER-SUBSCRIBE-REQUEST@PEACH.EASE.LSOFT.COM
> Anyone know how to change the colours in calendar, so that each day has a
> different colour? thanks.