It is a part of an adult's shed. They aren't eating all of their sheds now. When they were younger, they must have been eating every bit of their sheds, because I never found them. My wife even thought that we had some kind of rare albino roach every time we saw one that was white. Then I did some investigative reading and question asking. Found out that a freshly shed roach is solid white until their exterior dries. As they dry, they darken until they are back to the normal color. Kinda neat.
I got these with the intention of feeding off the young'uns to our bearded dragons. There are probably around 30 or 40 adults in the tub. I've had them for so long, I didn't think that they were going to produce anything. I was real close to getting rid of them and then the little ones appeared.
Best,
Red