I need some help please.
I've got this spreadsheet with different Types and Stages. Each Type has its own start date and there are six stages for each Type all with the same period between each Stage.

What I would like is a traffic light system so that:

3 days before each Stage is due the cell turns Amber,
during the period for each stage the cell is Yellow
once the period is over the cell is Green until the end of the last Stage.

I thought I had the Conditional Formatting correct but it doesn't seem to be working.
I know it all seems a bit mumbo jumbo but if you take a look at the link to the spreadsheet on Google Docs hopefully it'll become clear.

Thanks very much guys.

LINK - http://wnl.me.uk/A6IgF3