That would be completely inappropriate.

It would! They will do it anyway.

Letting anyone change castes, let alone reds, would be stupid.

Anitam isn't insisting, which would be unreasonable. They are just not giving anyone a ride to a colony planet from where they can embarrass Amenta in interstellar diplomacy.

That's a lot like insisting and they know it.

Aliens will in fact invade over this. It would be a catastrophe if Amentans were conquered by aliens who felt themselves morally in the right because of reds. It is not a chance they are willing to take.

How do they know so much about aliens?

They've met a bunch. 

How'd they do that?

The aliens landed and they talked to them. These are the ones who have to be anonymous because of Federation rules about that kind of thing.

Why did the aliens land in Anitam?

Unknown. Maybe it was because of Isel. She's good at reds stuff and the aliens are really concerned with that.

Are the aliens even themselves clean?

Daeva cannot ever die and do not ever use the bathroom. It is hard to make the case they are unclean. Other kinds of aliens may vary.

Places reluctantly agree to pay angels one way or another.

Oh good.

Some of them want the cleaned reds to leave afterward.

For where?

Some other colony planet? Is anybody taking immigrants yet, do they want them? Just not... around, cluttering up their original countries. Rivik is one of these.

There are demons who've looked into raising islands in the ocean without fucking up sea levels too much, right?

Yes! This is doable. It involves having cool undersea tunnels.

"Want to help me plan an island approximately here for all the reds whose countries won't take them?"

"I would love to." Cam does some modeling and designs up a nice island propped up on little enough below-sea solids to avoid messing up the sea level.

"You're the best!" And Telkam will call up fuckbuddies until he finds one who will make it for him.

Telkam has lots of obliging demon fuckbuddies who like him very much and the first one he tries will happily make this design.