Blue wheatens come from only the wheaten variety.
Blue Wheaten X Blue Wheaten = 50% Blue Wheaten, 25% wheaten and 25% splash wheaten
Blue Wheaten X Wheaten = 50% Blue Wheaten and 50% Wheaten
Blue Wheaten X Splash Wheaten = 50% Blue Wheaten, 50% Splash Wheaten
Wheaten X Splash Wheaten = All Blue Wheaten
Wheaten X Wheaten = All Wheaten
Splash Wheaten X Splash Wheaten = All Splash Wheaten
When you get to the Blue, Black and Blue/Black Splash, you have another series similar to the above. To make it even more confusing, the Splash from the Wheaten variety and the Splash from the BBS line are totally different colors/variety. Also, the splashes of both these varieties are not recognized by the ABC. I think they can be shown, but the are not officially Ameraucanas.
The Ameracauna is a relatively new breed. I think 20-30 years and took much work from the breeders to reach the standards that were set and agreed to by them. Therefore there are only specific colors/standards and to change this, much work/consensus is required. They have to go through several generations of breeding and get to the point where they breed true. Even then, as genetics work, there are some abnormalities. My Blue Wheaten roo that I bought as a day old chick from a well respected breeder is off color. He has red where he should have blue so he is basically an EE. I cannot use him to breed Ameraucanas. One of my Blue roos has gold leakage. Guess he might be considered Ameraucana, but I can only responsibly use him to breed EE's. You can go to the official ABC website and see the recognized colors at
www.ameraucana.org/scrapbook.html.
There are some of the original breeders on this forum and they can tell you all sorts of genetic facts, but it makes my head spin. I am happy to know what makes what and what not to mix. I got my first real AMs last year, but I have learned so much from this forum and also from the ABC website. Do not be afraid to ask questions because that is how you learn. I love my fuzzy faced flock and the blue eggs they lay.