If you earn Opal for 33 weapons ... Unlock Afterlife for every gun to unlock the fourth and final Mastery camo: Nebula. Slate ...

Black Ops 6 Zombies also has four Mastery Camos: Mystic Gold, Opal, Afterlife, and Nebula. Similar to Multiplayer, players will need to complete a set of challenges for each weapon to unlock them.

Then, the Opal Camo Challenge will need to be completed for 33 Weapons. This will then unlock the Afterlife Camo Challenges and the final set of Camo Challenges to earn the Nebula Camo.