Possibly silly question about soft egg color

[VeggiePetsitter]

First time chicken mom and two? of my six started laying this week. Rose (EE) laid lovely faintly pink tinged creamish eggs M, W, Th. Eloise (BCM) laid beautiful but tiny dark brown eggs T, Th. On Thursday before either of them laid someone left a soft egg in the corner of the coop. The color of the soft egg...err sac? I'm not sure shell is the right word lol is a very light brown with tiny darker brown bits that I can't tell if are speckles or bits of bedding and I'm not sure whose it is, whether they might come out darker than normal eggs and it could be Rose's or come out lighter and it could be Eloise's or if Penelope (welsumer) was starting up her own production but a lot lighter than I've seen pictures of their eggs, so I'm curious if the color of soft eggs is usually the same or lighter or darker than their normal eggs. The other three are olive egger (Violet), Americauna (Agatha), and a silkie crossed with something blue and supposed to lay blue 15/16 or cream 1/16 (Daphne), so it wouldn't be any of theirs. Any help in my attempts to figure out whose softie it was would be appreciated

 

[FluffyButts55]

If you have problems with soft shelled eggs in the future, she might have a calcium deficiency. Have you been feeding them eggshell or oyster shells?

 

[VeggiePetsitter]

If you have problems with soft shelled eggs in the future, she might have a calcium deficiency. Have you been feeding them eggshell or oyster shells?

I'm just asking about the color of soft eggs as it correlates to their normal egg color, thanks