Conditional formatting for 0 values

I have a similar issue.

I have a measure that works out an overdue rate between 0 and 1. This could be zero under two conditions: all tasks are complete or the due date is not yet past today's date. I have set the measure to be a "Decimal Number" and have tried several formats for it.  

I then have a date and traffic light indicator, which are separate cards that show the due date. 

The data labels for these are coloured based on the following conditional formatting rules (the date is formatted based on the measure):

For any non-zero value this works fine, however when the value is zero it default to blue text. If I change the measure to add an aribitrary 0.000001 and adjust the rules then the conditional formatting will be green for near zero values, which is my workaround for this ruleset.    

There is an exception on exactly zero.