The meats any good after the outer hulls have turned black?

Yes, the meat is fine after the hulls turn black. Just be sure to wear rubber gloves when removing the hulls. You can then let the shells dry for storage.

Even if the inner hulls are all black? Figured I'd find before I toss them to the squirrels. I'm using the outer hulls for trap dying

They should be fine, but if you want to be sure just clean a few up, let them dry, and then crack them open to see what the meat is like inside.

I was always told that the meats get a stronger or more bitter taste if you let hull on and allow the dye to soak into the nut. I don't know for sure though but it does make sense. I always thought they're to strong regardless!

kodiakbrownbear may be right. I might be biased because I've always liked the strong flavor of black walnuts. (I think English walnuts are too bland.)