EEs can come in ANY color combination.... but true Ameraucanas and Araucanas have only so many colors recognized per breed. (though there are sports and people working on new colors)
Actually colors are VERY limited. If you have the wrong color then it is not accepted as an Ameraucana....it's an Easter Egger. Check their website, it has a lot of good information and pictures.
I am not sure where to put this but I would like to say that this is the only place that I know of that you can ask the simplest of questions or a very advanced question and not be judged or laughed off the site. This place is AWESOME.