conditional coloring of pivot values depending on an external property value

Hi there,

I'm searching for a possibility to color the pivot values depending on an external condition.

To be concrete, I have activity data of certain chemical compounds. I have made indices for different residues on positions 1 and 2, i.e. property R1 has indices 1, 2, 3... and property R2 has indices 1, 2, 3... I have two different heterocycles as core structure that have the property "Heterocycle" and the value 1 or 2 respectively. What I want to do is to create a pivot table of R2 (PivotName) and R1 (MergeUsing) and the activity (PivotValue) BUT since I have to heterocycles I want the activity data of Heterocycle = 1 in blue and for Heterocycle = 2 in red. So for R1 = 1, R2 = 1, Heterocycle = 1 and R1 = 1, R2 = 1, Heterocycle = 2 I would have two activity data in one cell that I want to distinguish by color. 

I know how to set up conditional coloring in normal tables but this case is a little bit more difficult because the property Heterocycle doesn't appear in the table and I don't know how to connect it to the property "activity".

Thank you for any help!

Best regards,

André