I had precisely the same experience when I stopped coloring my greys last year. I lasted six months, until just about all of the dyed parts were gone, and then I caved and started dyeing again. The grey looks great on you, but on me, it just looks tired. And when I look in the mirror and see tired, I feel tired, and I need my energy more than ever these days. So I'm dying it dark ash blonde, will give it another few years, then try again.