Sort of correct - what the driver DOES allow you to do is to select colors for the top/bottom/toggle BUT those only work for attached keypads etc. - which is what I'm guessing OP means when he says he's changing settings but it doesn't 'do' anything.
Indeed, you cannot change the color of the LED on the bottom of essential devices, only the intensity or reveerse it's indicator function, or ave it off, or programmed, but not what colour it is).
I suppose I misspoke when I said you can do it on ANY C4 lighting, wasn't thinking of the essential line.