Questions about EE's, "Olive eggers", ect......

I have read that most olive-eggers are AmeraucanaXMorans cross breeds, or something along those lines. Are there any other breeds used to create this color? I was just wondering about the popularity of "olive eggers" and how much you might value them for........along with EE's. Just wondering, no big deal! My curiosity has gotten the best of me. Then, is it true that the blue egg gene, so to speak, is dominant? (Ex: you breed a blue egglaying ameraucana or araucana hen to a RIR roo, the result will be a blue egglaying EE?

Is this true? Or have I gotten confused........yet again?
Oh, and....to get an "olive egger" Would a Cuckoo Morans roo X Ameraucana hen bring about the same result? Or, does it depend on the egg color the Ameraucana lays?

Any information about either is greatly appreciated! And sorry about my lack of knowledge........but i gotta learn some how! Hope i posted this in the right area......

Yes, it will work either way.  An eggshell can have one of two base colours: white or blue.  The gene for blue eggs is dominant over the gene for white eggs.  The brown colour is due to any number of other genes and is basically a brown coating over top of the underlying eggshell colour.  So if you breed a blue egg layer to a brown egg layer, you will get a blue egg with a brown coating and the egg will look sort of olive green.  If the hen just adds a pale brown coating (e.g. if you cross with a breed that lays beige eggs) it will be a lighter green or teal colour. 

If you're breeding to a hen or rooster that carries two copies of the blue egg gene (homozygous for that trait), then all of the progeny will receive one of those genes and because blue is dominant over white they will all lay blue eggshells.  But if the blue egg parent is heterozygous (one blue gene and one white gene) and you breed to a white eggshell chicken (e.g. either white or brown which is actually white with a brown coating), then half of the babies would get the blue eggshell gene (they would be heterozygous for that trait) and half would get the white eggshell gene (and would be homozygous for that trait).

Most true Ameraucanas are homozygous for blue eggshells but the odd beige egg layer does crop up.  Many EEs are homozygous too but many are heterozygous and some lack the blue gene altogether. 

Bottom line: if a chicken lays blue eggs then you know it carries at least one blue eggshell gene, but you won't know whether it carries two (although a purebred almost certainly will).