The chick with the single comb, slight crest, and chipmunk pattern is the one I am talking about.Welsummer would have a single comb. That's the kind of narrow comb that stands up, and looks like you could comb your hair with it. Any chick with another comb type can NOT be a Welsummer.
Many chickens that lay blue or green eggs have pea combs. Sometimes their pea combs are little and tidy (like Ameraucanas have), while others are big and blobby (if the hatchery has been mixing breeds.)
If the chick turns out to have a pea comb, it will probably lay blue or green eggs. (Brahmas are on the list, have pea combs, and lay brown eggs-- but none of the chicks in the photos look Brahmas.)
A chick from that crossing would have a single comb and stripey down, just like both parent breeds have (and yes, would lay olive eggs.) So that is another possibility for a chick with a single comb, but not for a chick with any other comb type.