Awesome trifecta all around! And I agree with Fenrix: very dark on the balance--more DC than Marvel, if you will.
I think my favorite was "The Sea City Six", which was right up my alley, thematically. I loved it as a portrait of the different ways people struggle to handle the aftermath of a calamity. I already posted a long ramble recently on this topic on the "Axiom of Choice" thread, so I won't rehash, except to say I can't imagine how much worse the impulse to replay this stuff over and over in your head would be if you were a superhero genius who believed time travel might be an option. I'm not sure you'd ever be able to move on.
"The Colors" was suuuuuper creepy and pulpish, and I especially enjoyed the reading.
And "Zeptonian Baby" was adorable. I've been thinking about the mechanics of this new superbaby ecosystem. I feel like this story finds the Earth right at the start of the problem, when the new arrivals (hah!) vastly outnumber the grown Zeptonians. Ideally they'll reach a point where there's enough Zeptonian adults around to take over the task of adopting the newcomers, and the people of earth can regain their sanity, and maybe only opt-in to adoption if they really, really feel up to the task.
I got the cuckoo vibe too, Fenrix, although with the voicework here, I was more inclined to let my cynicism take a backseat. It's certainly an interesting take on an alien invasion, except it's so scattered. If you send babies that have the potential to grow up to be either superheroes or villains, it's not a very coordinated or focused invasion, is it? Unless, of course, the Zeptonians are unable to control their children any better than Earth can, in which case this story is a nice parable to the quality of Earthling parenting.