Conditional Formatting help with =Today()

Hi,

Please forgive if i am not finding the help i am looking for in the other forums, but i am still new to the conditional formating rules and formulas, and if this can be done with conditonal formating or does this need to be done in the VB coding side of Excel.

i am attaching a screen shot of my worksheet to show what i am trying to do

i am wanting to have cell f31 change to red when it is past the due date that is in e31, have it turn and stay yellow when cell e31 is between the date listed and 15 days, and then turn green if it is more then 16 days before the date in e31. any help is greatly appriciated