My sense, from exploring that website www.goinggraylookinggreat.com
is that the color of your gray depends a lot on how much of your natural color you still have. If most of your hair is without pigment, you'll have whiter hair. Shades of gray result more from non-pigmented hair reflecting underlying colors. So right now, since I still have a lot of my natural dark ash blonde, my hair looks a bit faded - the result of scattered grays throughout. And I'm okay with that.