A million shades of Grey

With the big move coming up, I've been pondering what to do with my upcoming unemployed status. While hunting for a new job in my new (old) home, I'm thinking that it's about time I catch up on my Quilting Bee quilts. So, I've been putting together the parts to make sure I can keep myself entertained.

One of the projects I hope to finish up soon, is my Mondrian quilt. The blocks have started coming in so now I have to start thinking about sashing etc.

Here are the first few blocks that I have already recieved from the Eurovision Ladies (well ok, I made 1 ;) ), gorgeous eh!

I already have the back at least partialy planned, it will be in part this fabric which we are going to use as table runners at our wedding reception (assuming our guests don't get too carried away with the red wine!), Paula Prass' Flights of Fancy trellis in Lime.

So now I have to figure out what to do for the front sides sashing. I bust out my Kona colour chart (love it!, best 5$ ever (ok maybe a slight exaggeration, but it's great), to sort which colour to use.

I'm thinking of greys... but I can't decide on which one... Charcoal, Coal, Medium Grey. or Ash.

From the R. kaufman website, I'm thinking of adding one of these greys to my current pallet.

In reality the lightest green is a better match to the other 2 ... the real colours are here:

So, what do you think... which is the best grey.... or do you have any other sugestions, sound off!