I make extensive use of customer filters using drop down of SystemUser attributes.
Example from V6 -- notice "Feeder" is the only filter with a value and it is highlighted yellow:

In V6 it was possible to use put conditional colors on a drop down reference.
This is V8.4 rough filter example:

I have not been able to find a way to put a background color conditionally (When the attribute is defined, turn the specified color on) on the value of a Combo-box. In this example, I would like to highlight the School attribute yellow.
Any ideas?