These aliens are actually an Amentan variant kidnapped from Amenta during the Stone Age by some other aliens who have since learned their lesson about not kidnapping Stone Age people. The descendants of the kidnapped have changed enough to look interestingly exotic but not so much that when some of them make a pilgrimage back to Amenta to see how it's getting on they can't marry locals to merge political dynasties and have half-interestingly-exotic babies!

Cute. The other one was more fun, though. Biologically implausible hybrids would be even better...

This book is authorized fanfic of a really dated one from 3418, wherein those protagonists already had biologically implausible hybrids via genetic engineering. Their half-green half-alien baby is back on Amenta trying to supply a museum with Amentan artifacts and falls for an Amentan blue who's on the board of a museum she's trying to buy stuff from. The blue's not initially interested, because the last time these aliens were here they kind of fucked off with their love interests and didn't help the general Amentan public at all, and she isn't up for abandoning her people. To impress her, the alien figures out how to get a planet for Amenta to colonize and then they finally hook up.

That's...sort of interesting...is the implication that the other aliens could have done this too and just didn't see a reason to bother?

Yup. It's billed as a fixit sequel.

It doesn't seem very fixed if the only reason alien jr. is doing it is to impress a romantic interest but valid. 

What is there set in Calado?

This one (by a non-Calador author) has Calado fuck up first contact, get conquered by a coalition of other countries about it to placate the aliens, and have several of its people offered as tribute. Slavefic ensues extremely tropily, with the perspective character blue boy handed around between various aliens being mostly-pornily mistreated until finally a nicer one gets ahold of him and owns him with a higher ratio of kink to mistreatment. This fic does not feature babies, a rarity in the genre.

Jesus. What else?

This Calador author has produced a historical fiction series on the theme set in what is now Calado during the height of the Oahk Empire! The aliens don't have planets handy to offer, and instead assist the Empire covertly to get population control implemented so that Amenta will be able to openly meet its neighbors, having attained this necessary social technology. (The aliens insist on it being managed by local efforts, since extraplanetary imposition of population controls has tended to go badly.) The protagonist of the series is a fictitious granddaughter of the Emperor who herself has a baby every year with her alien paramour, though.

Huh. That seems kinda selfish given the givens. What else?

This one is set in modern Calado with a preexisting Amentan couple, property blues, encountering aliens with the power to visit dreams, via, of course, dreams. Through rather trippy and unclear dream communication the couple negotiate the aliens' contact with Amenta, and convince the aliens that the permissions system is the most eugenic and must be practiced on all colony planets, and seduce a couple of the aliens.

...

Next.

Next she has an email from Delin with her proposals for greens to send to talk to her about things, so she can read their faculty pages and screen them if she wants.

Ooh, excellent. She reads some faculty pages.

I teach introductory and general classes in theology, but my principal interests are the theology of care, theology of caste, and speculative xenotheology; I was a consultant on the television serials Aloft and Sea Neighbors.

You can download my papers on anthropology by decade, by topic, and by coauthor, but none of those lists contains all my work; for a complete list see papers by publication date...

I've contributed to political philosophy anthologies, private sociopsychology think tanks, and the International Commission on Social Science's omnibus of work on class differences across countries. I currently teach classes such as Class And Caste, Class and Language, Voan Sociology, Pre- and Post-Imperial Permissions Dynamics ("the darha course"), and Global Democracy, in addition to lower level coursework.

My specialty is evolutionary biology as applied to tropical mammals, but I also consult on speculative xenobiology for authors such as...

She pores over the bios and gives each one a supplementary Citrus search. 

The first one is enthusiastic enough about the prospect of exterminating reds that she has to go punch something to avoid snarling about genocide. The third one is...a hardcore eugenicist with four children, okay, she's sure there's no motivated reasoning there at all, ah huh. Those two will be filtered out, thank you. She also vetoes one with an especially obnoxious writing style. 

This leaves her with the evolutionary biologist and the possibility that Denlin has other greens available if she digs a little deeper.

Evolutionary biology sounds fun. She's going to want to talk to people in other fields eventually but she's not in a hurry. 

Denlin assumes she'd like to meet on her turf, is that correct?

It'd be preferred, yeah, but it's not required if there's reason not to. 

There's not, she can be delivered an evolutionary biologist!

He arrives that afternoon.

She greets him at the door with blue hair that changes back to black as soon as it's closed again. 

"Hi!" 

"Hi - wow - I didn't really believe -"

"I'm pretty unbelievable." 

"Delin actually gave me a list of a bunch of different outlandish things it could be - told me it was one of them - and it's you! You're from space! I suppose!"