In game support told me via email to file a bug report concerning the issue. I was the seller Hag@Nautilus777, I have not taken the AD from the ingame mail service in case they needed to know the @handle of the person that bought it. I assume that support will , or can't roll back my character in hopes of retrieving my…
I don't know if there are any dyes that give that effect. But the armor enchantment soulforge adds a shadowy movement over your person whom it's equipped to.