who laid this egg?

I bought two EE'S I found on craigslist a few months ago, 1 is americauna and the other auricana (probably not spelling right, I see them spelled differently all the time) I also have a partridge rock, and a yokohoma that I see going in the boxes. However I see the americauna in the boxes most but the eggs I'm getting aren't colored. It's a light brown egg covered in white speckles, inconsistent laying days and times. The very first egg was darker, second egg (2 days later) was pinkish, 3rd egg (day later) was light brown with darker brown on other end and 4th egg ( today) is very light brown. So I'm wondering if my americauna is mixed with australorp or if it's my partridge rock laying. If anybody has partridge rock, yokohoma or EE'S laying brown eggs can you leave egg pics please?
Also, my brahma rooster watches over the ladies as they nest...strange right? Haha
Today's egg.

First egg, second egg and today's egg.

Could she be americauna x australorp?

My rooster watching over the ladies as they play in boxes

Judging by the color and shape of the eggs, it appears as if you have two hens laying. Since EE are crossbreds not all of them lay blue/green eggs.

sourland said:

Judging by the color and shape of the eggs, it appears as if you have two hens laying. Since EE are crossbreds not all of them lay blue/green eggs.

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X 2 -- a quick physical exam can help you ID which birds are and are not actively laying -- the size, shape and condition of the vent, the spacing of the bones near the vent, etc are all things to be evaluated.
On the issue of your EE - - Ameraucana and Araucana are both pure breeds -- they are breeds that are sometimes used in the creating of Easter Eggers (which are mixed breed birds with blue egg parentage on one side of the equation). Both the pure breeds do lay blue eggs, but EE can produce blue, green or any shade of brown (which includes pink, purplish, cream, brown, etc)