I notice that you found the layer and she lays a beautifully speckled egg!
I am not sure about soft brown eggs as my one brown layer has always laid perfect eggs that range from light pinkish brown to an orangish brown.
Something I have found about soft eggs of the blue variety is that some of the soft ones I got from one of my blue layers are very bright darker blue than her hard ones.
I have 2 blue layers and they are different mixes. Dove's eggs tend towards powder blue but sometimes a slight bit of yellowing to be an almost mint color, she has had some shell issues and most of the softs were almost too bright to be true. Very striking. The Nuzzler has had a few softs and hers are more of a light greenish to just about white. Her hard eggs can range from the faintest blue to an almost olive color. She makes quite a thick membrane and some of her egg shells are so thick that they are hard to candle, impossible with the phone light at least.
I was reading that one chicken lays the same color egg but have found that there can be quite a variation even with the same bird considering membrane, shell, outer color, and bloom I guess.