Yes, there's a better way than Visual Cues. You can click on the + in front of the expression (on the Expressions tab) and click on Background color. There you can enter an expression using the dimensionality() function. If you want to see what that does add an expression to your chart =dimensionality(). You'll see that the partial sums will have a lower number than the detail rows.
You can use that in the expression for the background color. Something like:
if( sum(MyValue) > 200, red() , green())
Change sum(MyValue) > 200 to whatever is appropriate for your situation. Depending on the number of dimensions in your pivot chart you may need another number than 2 in the comparison with dimensionality().