Okay - the colour DpprDr posted is the one I want - so slate must be it. I think cloud must be the lighter grey colour that I still like very much, just not quite as much as I like the darker slate.
Thanks for the help gents.
LOL - no offense, Namor - I like the cloud a bunch, but I am craving the slate in a next-buy kind of way. If I were to add a second grey pair down the road, cloud would be it.