Here's that chart Cowgirlgrace; as you can see, color is highly variable and includes blue, shades of gray, and shades of green. You can order this from the Ameraucana Breeder's Club for your own reference as computer monitors do vary. I think John Blehm listed on his website that the silvers had best egg color at his place, earning a score of 5 out of 5.
I will now hush and turn this topic over to those with more experience than myself!