That's part of the deception of store packaging:
The brined meats are stored and sold in cryovac packaging with the brine, which forces an equalization of liquids - juices native to the meats are pulled out of it, while the brine is forced in simultaneously, homagenizing the strata of brine exposure you see, combined with, often, weeks of the corned brisket setting in the brine in packaging either at the processing plant, a distributor's fridge, or a retailer's meat locker.
Plus some of the grey being seen is partially oxidized meat, because it wasn't in an environment entirely absent of air (which isn't a bad thing!) salts, nitrates, and acids react differently in the presence of oxygen than in the absence of it, and so your brine was more "active" as elements in the brine were interacting with the air in your fridge.
I saw the same kind of lines last time I did pickled pork, and it turned out fine!
The biggest indicator of something gone wrong would be the smell, at this point.
Originally Posted by eman
If you are talking about corned beef from the store the ones i get are red all the way thru but not blood red like beef.
I dont use liquid cures on meats so it maintains the same color while it cures. When i buy corned beef it is red .
But then when i soak it to remove the salt it washes all the blood out and turns it grey.
All i'm saying is that the grey color on the outer portion of the meat you have is caused by the blood leaching out which is then replaced by the curing liquid. If this is so then it stands to reason that since the center portion of the flat is still blood red then the cureing liquid did not reach this point in the flat in sufficiant quantities to leach out the blood.