Conditional Formatting leaving cell blank if doesn't meet requirements

Hi I am having some issues with the following spreadsheet (please see attached), what I would like to happen is this:

In Coloumn N, I want the cell to highlight red when the date entered has expired, for example if the date in coloumn N is 08-07-13 it should show up red because the date is now 12-07-13.

Also in Coloumn N, I want the cell to highlight green when the date entered is still valid, for example if the date in coloumn N is 17-07-13 it should show up green because the date is only the 12-07-13.

And lastly in coloumn N, I want the cell to highlight pink when the date entered is the same day. for example if the date in coloumn N is 12-07-13 it should show up pink because the date is the 12-07-13.

Now I have managed to get the above to work however, if the cell is blank I want it to remain blank and at the moment it highlights green.

Can someone please help with this??

Regards
Rhiannon