Conditional Formatting on another cells date value to the current cell date

Hi,

I'm trying to do a conditional formatting where if i.e. col A has a date in it, if it is more than 28 before col B's date, it highlights green.

I have been able to do my 2 others where if it is 3 weeks before, it shows amber and if it is 2 weeks or less it shows red but the green is only showing the exact 28 days and not anything more than that.

It is also showing the cell as green when there is nothing in col A which I don't want, I want it to be no colour.

I've attached my example spreadsheet which has my current working formatting.

Can someone help me please, it's driving me nuts trying o figure it out!!

Thanks

It seems to have done it. It is still making my cell green when A is blank though?

Any ideas?

jennys,
See the attached. I changed the green formula to include an if statement, so excel says "if there is a non-zero value in A, is it greater than 28 before B? If there is no value in A, it puts in "NA" (text value) and the test fails."
Tell me what ya think.

excel example.xlsx