Idk how accurate this but have u heard of blacklighting a BEL? I saw elsewhere on the forum that it reveals patterns too faint to see so u can tell if there's any pastel involved... idk if it works so forgive me if this has been disproved great looking snakes though!!!
I'm not sure what good a blacklight would do to ID pastel, since it's more of a color morph than a pattern distortion. Beautiful babies, though!