I'm still trying to learn all my ball python genetics and there's soooo much overlap and variance in the morphs...So I hope a breeder can correct me if anything.
But from what I've seen, pastel is one of those genes where it doesn't always display as written. There's a good amount of blushing on the darker patterns and the back of the head is so pale. But it still isn't as light as some killers.
It could just be a lower quality visual killer. But the only way to be sure is by breeding it out. Obviously the killer would throw all pastels in a clutch.
If it was my hatching, I would sell it as a high visual pastel clown, possible killer. That way all your bases are covered in case it does indeed just turn out to be a very nice pastel.