Coloring rule in cross table based on underlying data table

Coloring rules are based on the rows in the cross table (and not on the rows in the underlying data table) - Grand total values in a cross tables are aggregated from the rows in the data tables. The user is unable to create a coloring rule based on a custom expression which is relative to the grand total value because he cannot access the underlying data. He wants to be able to do this. The coloring rule states that every value that is lower than the "average" should be colored red, however, the "average" is an average of the values in the cross table. D3 / NE for Ach% is 84.4% and not colored red even though it is lower than the grand total value of 84.5%.