I've never really had a calcium deficiency problem here (except occasionally with a new layer) but the eggs are literally decorated...I wouldn't imagine you could mistake the two if compared. More often than anything, I find a calcium deficiency usually comes in the form of an egg with no shell...
I'm going to guess that it's either your Red Star or your Orps, mainly because I get up to two speckled brown eggs a day, 3-4 times a week and we just added those two breeds to our flock this year. They are the only breeds we have in common with yours. Our eggs are a light to medium brown with...