@BantamLover21, Good question. I ordered from Meyer (first time trying hatchery chicks via the mail) and I ordered late, so ended up going with a couple of specific breeds I wanted and some mysteries. I ordered eight of their Mixed Rare Breeds (which were packed as 4 male, 4 female, but I don't know anything beyond that) and eight unsexed "could be anything" (LeAnn's Grab Bag). So possibilities are limited to Meyer Hatchery birds, but that's it!
The comb is single (and a little less bright than this photo shows, I think the camera was on "vivid" setting) and as you can see, the toes are half pink, half grey (the toes actually look a lot like my Andalusian's). I hadn't thought of Blue Langshan, after looking at some photos, it does seem like a possibility!
EDIT: After looking at Meyer's site, the only Langshans I see are Black (and they're not available this spring), which makes me think it's unlikely (though perhaps not impossible if they have small #s of some chicks or breeding programs ongoing and any of those go out w/ these mix orders since they leave that possibility open in their description?).
Any idea what I should look for as the weeks pass to distinguish this one?