Q: Can I Set Submix Label Color

I would like to be able to set the label color as can be done with tracks, and clips.  At the moment, all the submix tracks are the default green.

Is there a way to set the label color? 

In the manual, there is only a mention that the submix tracks have a color label, but no mention on how to change it, and cntl-click does not review a pop-up menu, and using the "Multitrack > Track Color" menu, has no effect.

To me, is seems if a track has a color label, I should be able to change it...

Any help would be greatly appreciated.

TIA