Conditional formatting based on number of days in SSRS against a cell value in reference to another field
You will need to come up with an expression for your fill color of that cell or field you want to change. So an example:

The basic setup is I just have 2 variables to enter a date and then a text box on the body of the report I will adjust the fill color based on the days between those two dates:


So I go into the text box properties and find the Fill page, I will set the "Fill Color" to this expression:

=IIF (DateDiff("d", Parameters!activity_date.Value, Parameters!valid_to.Value) &gt; 14
,"Green","Yellow")


Then my result:




In your case you will just build out the "IIF" to follow the criteria you have for your formatting.

This is just a guess from doing it in my head (and writing it out in Notepad++) but I think this should be what you are looking for:

=IIF(Fields!valid_to.Value = Today() AND IsNothing(Fields!cell_value.Value) = 1, "Red",
    IIF(Fields!valid_to.Value &lt; Today() AND IsNothing(Fields!cell_value.Value) = 0, "Orange",
        IIF(Fields!valid_to.Value = Today() AND DateDiff("d",Today(),Fields!valid_to.Value) &lt;= 14, "Yellow",
            IIF(Fields!valid_to.Value &gt; Today() AND IsNothing(Fields!cell_value.Value) = 0, "Blue",
                IIF(DateDiff("d",Today(),Fields!valid_to.Value) &gt;= 15 AND IsNothing(Fields!cell_value.Value) = 0, "Green","White")
                )
            )
        )
    )