
The Liquid Rainbow is a miscellaneous crafting material in Diablo III, used to construct the Staff of Herding which is necessary to access Whimsyshire.
"The colors swirl and twist in hypnotic patterns."
It is found in a Mysterious Chest in the Mysterious Cave which sometimes appears in the Dahlgur Oasis of Act II, in both Campaign and Adventure modes. It is guaranteed to be found in the Chest, and drops account-bound for every party member. However, the Chest only appears in the Cave some of the time, and the Cave only appears rarely.
Acquisition[]
This ingredient can be very difficult to obtain, since the appearance of the Mysterious Cave and the Mysterious Chest inside is random. There are several possible approaches, which all rely on repeatedly loading a new game session ("Leave Game" then "Resume Game") until the Cave and Chest are found.
In Adventure Mode, new game sessions can be created until the Act II map shows a bounty to clear the Mysterious Cave. It is possible for the Cave to be in game without being a bounty, so an actual spawn of the Cave may be missed this way, but it saves the trouble of physically checking the spawn location.
When not actively farming for the Rainbow, it is wise to check nearby spawn locations for the Cave while doing other bounties in the zone.
The other active strategy is to simply check one or both spawn points for the Cave, then reload the game if not present. It is more reliable to do this in Campaign Mode, where the "Path to the Oasis" waypoint is guaranteed to be reasonably close to the southern spawn point, and a second waypoint is in the north as well:

Top Left: Location of Cave Entrance (From Path of Oasis waypoint, Act II); Top Middle: The merchant in trouble, you must save him; Top Right: After saving the merchant, he will open the door; Bottom left: The mysterious chest, looks similar to Resplendent Chest; Bottom Middle: Map showing that the chest can be on first (or second) floor, and may even spawn near the entrance; Bottom Right: Liquid rainbow item from inventory
- Make sure the game is set to the seventh quest ("Blood and Sand") or later. There will be no NPCs or quest events if set to the eighth quest, "The Black Soulstone", on the "Soulstone Chamber" stage.
- Travel to the "Path to the Oasis" waypoint, which is in the southwest corner of the Dahlgur Oasis of Act II.
- If the last game session was exited from the Dahlgur Oasis, a handy portal will lead back to the same location from town.
- Head southeast to a short path leading to a watery nook (see image, top left).
- Look for Zaven the Alchemist, who must be saved from Deathly Haunts. He may be hard to notice among the monsters, since initially he is cowering to one side and the Cave entrance is not visible.
- If not found, the second spawn location may optionally be checked as well, although it is not as quick as the first:
- Teleport to the "Dahlgur Oasis" waypoint, which is in a random location to the north in the zone.
- Head to the second location. It is helpful to know the layout of the zone well to be able to head directly to the correct nook regardless of the waypoint's exact location. The map may be helpful since the area from the first check will be revealed on it, serving as a reference point.
Zaven and the Mysterious Cave do not always spawn, in which case a new game session is needed. Spawn rate is estimated at 3-5% at each spawn point in Dahlgur Oasis.
Once Zaven is found:
- Kill the monsters around him. He will stop cowering and a blue exclamation mark will appear above him.
- Talk to him, and he will open the door to the Mysterious Cave.
- Explore the rather large, multi-leveled cave and look for the Mysterious Chest. This is not the Resplendent Chest found at the end of the dungeon; both may coexist. The Mysterious Chest does not always spawn, just like the merchant. When it does, it usually spawns in Level 1 of the cave, but Level 2 is possible also.
- The Liquid Rainbow will be always be found inside the chest.
If the Mysterious Chest is not present, then a new game session is needed once again. Spawn rate is estimated at 20-50%.