Mage Tower Artifact Variant colors

I unlocked the mage tower artifact appearance on my death knight, but I’m no longer able to unlock the the other tints. I race changed the dk and also deleted/ restored, so maybe that caused the issue.

Did you try physically equipping the artifact weapon, going to your class hall, and changing the artifact skin there, without the use of a transmogrifier?

I’m assuming you’re talking about the mage tower skins for the spec you completed it in from Legion.

You do have to visit the forge with the artifact equipped once in order for the tints to get added to your transmog collection, this is correct.

I did physically equip the artifact, but now the entire row for the character has the grey X on it showing it as being unobtainable despite having the base mage tower color prior to race changing and deleting / restoring

There’s a Blue Post in response to someone that sounds like a similar situation to what you’re describing, but I feel like I’ve seen multiple people losing their artifact appearance after faction changing, so that’s why I’m not entirely convinced the solution is a complete UI reset as suggested by the Blue Post.

Since Mage Tower unlocks should be account wide, have you tried creating another DK or 2(of each faction) to see if you have the appearance available to them? If so, maybe try mogging a weapon to the appearance, and then check back on your original DK to see if it’s available again?