Island! Outrageously tall skyscrapers that only demons can make!

...and Rivik et al can dump reds there?

It is his country. It will take all immigrants except blues, who can universally as a caste go fuck themselves. It does not have castes. Immigrants from Rivik et al are welcome.

Isn't he sort of arguably blue?

No.

He kinda is.

And his interlocutor is kinda arguably red in that if they get themselves killed in an argument over something stupid they will be unclean.

If he's not blue he shouldn't have a country.

What're they going to do about it?

...find him in violation of global treaties?

Oh boy.

And... sanctions? And strongly worded letters.

Rivik dumps terrified clean reds whose hair grows in every non-red color of the rainbow on him anyway.

Fairies are harder to pay with sex but he arranges one to hang around in case anyone decides to escalate from strongly worded letters to airstrikes. 

He goes down to meet his terrified clean reds. "Hi," says his translator. "Did you shitty government explain anything at all or did they just grab you."

...they are anxious and timid! But one says "They said we should tell the angels what color we would rather be."

"Great! Okay. So here you are on the new continent which the aliens helped me raise out of the sea. It has houses - "gesture at the ridiculous skyscrapers - "I'mma just give them out, one less thing for people to worry about. Technically this country prohibits blues but I guess I can make an exception for ex-red blues."

The ex-red blues look nervous anyway.

"Laws! We've got two. Don't hurt people, don't take their stuff. If you're starving you can take someone's stuff but you shouldn't be starving, my brother's working out a thing where every month you get enough money to pay for food and medical care and clothes and stuff, just automatically, even if you're not working. We don't have population controls; we can fit maybe fifty million people and then we'll get ourselves a planet once it starts to get squeezed."

The ex-reds look at each other.

"Any questions?"

"...is caste matrilineal or patrilineal here," asks an ex-red blue.

"Caste goes by hair color. Not what it naturally comes in as, whatever it currently is."

Soft murmuring.

He waits.

"...what do we do if we have a problem?" asks the same new blue.

"What kind of problem? Someone broke one of the laws, I'm being the courts until we get courts set up. Someone's sick, I assume you guys have doctors? They can look online for a hospital design they like and then I'll get the aliens to build it. The trains are running late, dunno, maybe someone'll want to take charge of train repairs and then make money off the fares."