[AccessD] Conditional Formatting with date

I have a report that displays a derived date (FollowupDue) which is 
calculated as (=DateAdd("d",180,[Closed]))  that I would like to provide 
conditional formatting for.

What I want to do is - If the date is between 120 to 149 then display the 
date as Green, if between 150 to 179 then Yellow, and finally if equal to or 
greater that 180 display the date as Red.  Using the Conditional Formatting 
dropdown if I am doing the greater than (Now(0)) is Red works okay.
Any of the other options does not work.  Is anyone familiar with this area 
and can help?

Thanks

John