The appearances also range, depending on activities you complete. For example, some are unlocked by participating in PvP, and others are unlocked by working on your Class Order Hall campaign.

I’m going to explain what these different appearances are, and how to unlock them. There will be a separate guide to show the hidden appearances.

This guide will go over unlocking alternate artifact weapon appearances in Legion including:

Types of Appearances - The different appearances you can unlock. Unlock Requirements - How to unlock the different artifact appearances.

Types of Appearances

Each weapon will have 4 normal appearances and 1 hidden appearance at launch. Each of these appearances will have 4 different tints, which are just different colored versions.

Classic - Starting appearance

Upgraded - An upgraded appearance involving completing your Class Order Hall campaign

Valorous - Different variation involving completing PvE activities

War-Torn - Different variation involving completing PvP activities 

Unlock Requirements

The requirements to unlock each appearance is the same for every weapon, except for the hidden appearances.

The header video by BellularGaming shows what every artifact appearance looks like in the game.

Check out wowhead to match the appearances to the requirements. The pictures below are of the Affliction Warlock artifact appearances.

Classic

1st Color - Obtain the artifact weapon 2nd Color - Return 1 Pillar of Creation You can obtain a Pillar by completing the quest line of any of the 5 zones. 3rd Color - Return Light’s Heart to your Order Hall You get this by completing the following quest line: A Falling Star, Bringer of Light, and Light’s Charge. 4th Color - Complete the first major Class Order Hall campaign effort

Upgraded

1st Color - Complete your entire Class Order Hall Campaign 2nd Color - Unlock every artifact trait There are 34 traits you need to unlock. The bonus traits you unlock afterwards are not required to unlock the color. 3rd Color - Research the full history of your artifact in your Class Order Hall This requires you to complete quests to unlock Artifact Knowledge.   This first is called Hidden History, the the second one is a quest that requires you to place a Research work order. 4th Color - Obtain 8 of the 13 rare archaeology finds in Legion. You must be 110 to start this and it is a part of a story line that updates throughout the course of the expansion.  

Valorous - PvE

1st Color - Complete the quest line, Balance of Power This starts at level 110 from your Class Order Hall. 2nd Color - Defeat 8 of the 10 world bosses in Legion 3rd Color - Complete a challenge mode dungeon using a level 15 keystone 4th Color - Complete the achievement, Glory of the Legion Hero This involves completing 26 achievements in Legion dungeons on Mythic difficulty. It is account-wide, so you only need to complete it once for all characters and weapons.

War-Torn - PvP

1st Color - Reach Prestige level, Rank 50 and complete the quest, The Victor’s Spoils This is a new system in legion that involves earning Honor. 2nd Color - Reach Prestige Level 5 and earn a Crest of Heroism This can only be obtained in PvP season 2 of Legion. 3rd Color - Reach Prestige Level 9 and earn a Crest of Carnage This can only be obtained in PvP season 3 of Legion. 4th Color - Reach Prestige Level 13 and earn a Crest of Devastation This can only be obtained in PvP season 4 of Legion.

That’s it for the Artifact Weapon Appearances guide for World of Warcraft: Legion. Let me know if you have any questions!