Help: Status update from a reference sheet with formula

Dear,

Can anyone please help me, I am trying to create a formula to generate a status update based on end date from a reference sheet (name: Cloud).  

=IF({Cloud Range 2},"Complete" <> 1, IF(TODAY() - [End Date] > 0, "Red", IF(TODAY() - [End Date] > -3, "Yellow", "Green"))))"

I have added the header of the sheet I am trying to reference from.

Many thanks in advance.