About the only way Ive found with OL2003 to get any decent highlighting is to
go into the calendar options and make the background color white (and grey)
for the most contrast with the grey shading bar across the top of a today
date on the calendar.

Ok sorry, more info--

It looks like the highlight bar is the same color as the Theme's grab bar
color.

But I've discovered I have a really weird problem:
When I go to the month calendar either by the menu, its shortcut, or folder
list,  I see a very brief flash of the highlight bar on the current date.  
After the flash, it disappears.  If I then select View/Current
View/Day/WeekMonth the highbar comes back and stays.  (Note that
Day/Week/Month is already checkmarked in the menu.)  My Outlook says it is
2002SP3.  The only thing I've done to Outlook is add Lookout, but that was
after Microsoft bought Lookout, so that can't be a problem.  Thanks for your
help!
Mike

One more interesting thing:  if a date is selected with a mouse click, the
highlifhgt bar moves to that date.  But if the Calender is scolled
vertically, the highlight doesn't stay on the date, instead it stays in the
same date location on the screen jumping/scrolling  week to week.