Return of Reckoning

So I haven't played in ages and now after returning an getting some new armor I want to dye it.

The problem is the vendors who dye your items don't have the dye I used previously on all my armor pieces. Checking the auction house shows nothing either.

The dye in question was Naggaroth Abyss Blue, the problem being I can't recall where I even got it, nor got enough of it to dye my whole armor fully. I can't recall but I don't think I bought it through the auction house.

So is there a vendor that I am missing/not recalling? Can anyone tell me where I can get the Naggaroth Abyss Blue dye?

Thanks!