So the Farrow and Ball "borrowed light" turns out to be a really pretty pale blue-gray with a tiny bit of green. Very scandinavian and certainly unisex. Seriously considering for kids' room. I'm posting here alongside rug of the opposite temperature to show how much the rug color is going to influence the feeling of the room.
Imagine Borrowed light walls with warm rug:
Or tissue pink walls with cool rug:
This balance is what I'm going for so it feels cozy and peaceful rather than like a baby's nursery or overly gendered.