Correction, this was the code I was using: if (event.value=="UL") event.target.fillColor = color.red; else if (event.value=="ML") event.target.fillColor = color.green; else if (event.value=="IL") event.target.fillColor = color.blue; The other code did not work at all. 

Sorry, meant to leave a comment not a solution...

For some reason the following code only seems to highlight the active form field. In other words, as soon the cursor moves to another form field the background color reverts to the default color. However, if i move the cursor back to the field with the conditional formatting the color pops back up??...