I know nothing at all about ducks, but I do know that this breeder has an excellent reputation and is probably where I would buy if I decided to try ducks. Steve Sands at S&S Poultry is another good choice.
I remember someone here has an Emery Penciled, but they are not a very common color. Holderread's has also just sold them as part of the Runner assortment, not separately unless as adults in the Fall/Winter (although I'm sure you could try to request some as part of the assortment and they might be able to). Your best bet might be google for that color. The difference between the Emery Penciled and the Penciled is the same difference as between Dark Campbells and Khaki Campbells (the addition of the sex-linked brown dilution). Search for pictures of Dark Campbells and imagine that in Runner form with the Runner pattern (if you can't find many good pictures of the Emery Penciled).
That should give you some idea of what they look like. The colored portions of the plumage for the most part just appear darker than those of the Penciled Runner. HTH.