Asmat Tribe

I'm just posting all 3 clues here so I can cross reference them. Fairly sure it has something to do with Kelimutu, or another Volcano.

Clue #3 wrote:
Not worth much but magical to behold
Climb up the slopes and find treasures untold
This chase is overheating, will you make it in time?
Dive into the rainbow and immunity you'll find.

Hidden Immunity Idol Clue #2 wrote:
This is long overdue, safety may soon disappear.
The third round is a clue too, but not crystal clear.
Can you find safety in numbers, will you find where immunity is hiding?
Don't stall, it might be your fate they're deciding.

A place or a person or a thing or a year?
No answer in this first clue to be given, I fear.
But a clue it remains, I'll tell you where to begin.
Ignore Java, overrated, it's the Sunda I'm in.

I'm getting close I believe. 1883 eruption of Krakatoa is related somehow. The rainbow could be the coral reef outside the island underwater. The treasure was part of lore on the island. i just need to piece this together.