Pic of dad? What was mom sold as? She looks maybe YB + a brightening morph of some kind. Did you breed dad? Any chance he is mom's offspring? Either of them acquired from NERD? I've got a few theories but nothing that could easily explain what's going on. It's a very puzzling situation, especially given that 4/6 turned out that way and not just one. Crazy odds do happen, but what are the chances that dad has an extra morph past what you listed, mom has a couple, and 4/6 babies inherited ALL of the possible morphs except spider? What are the odds both mom and dad have a recessive and 4/6 babies got two copies to show visuals? Both scenarios are extremely unlikely.
The reason I ask about NERD is that Kevin has something floating around in his lucifer lines that has a very similar look of dorsal stripe, and lucifers can get blue eyes in some combos that otherwise wouldn't have that. Lucifer + pastel + YB might explain how strong the head blushing is since I highly doubt mom is pastel based on her pic, so they can't be super pastel after all.
Here is a pic of what I am talking about with the dorsal in NERD lines:
So far all I'm certain of is those hatchlings have GHI and a single copy of pastel. The rest is just guessing, but probably YB, not spider, and something(s) else. If it were me, I would certainly be keeping a few of them, if not all of them, and doing some test breeding to figure out what the heck is going on, or at the very least, partner up with an experienced breeder who could help you do that.