I have a theory about the SIVA offerings: The color of the actual tube (not the rarity color) represents the type of offering. You can tell what type they are by reading the text of the item, but it would be nice to know at a quick glance what type you have to help complete Shiro's bounties.

So I need a little help to test it. Currently I have an orange offering that is a Shank encounter, and a red offering that is a Vandal encounter. What color offerings you have and what type are they?

Btw: the first SIVA offering I received was Perfected. Not knowing any better, I went to the Forge and gave it a whirl. Needless to say, it did not go well.

Btw: the first SIVA offering I received was Perfected. Not knowing any better, I went to the Forge and gave it a whirl. Needless to say, it did not go well.

I had a similar experience last night. I had an offering with a purple background and yellow/orang vial. I gave it a whirl and wiped hard with enemies at a much higher light than I am.

Finally just looked in the DB (don't know why it took me that long to figure out). Each color has two possibilities of which one you have (it's still written on it what it is though).

Yellow/Orange: Dreg or Shank
Red: Vandal or Captain
Blue: Servitor