I don't ship Hades/Odette-in-any-form because I just... can't. I like him as a character and I find him interesting in a 'pin him under glass' kind of way.
(Odette is a lesbian, also, but I don't think all shards need to have the same sexuality because why would they. But that said I def don't ship Leuke/Hades as it just doesn't satisfy me the way I like ships to)
In Greco-Roman mythology, Leuke was a nymph (an Oceanid) that Hades fell in love with and spirited away to the underworld. This feels familiar. When she eventually passes, after her full life, Hades turns her body into a white popular tree in the Elysian Fields. As such, white poplars became a symbol of those we loved who have died as well as hope for a peaceful afterlife.
(This is why I mentioned shipping.)
I think, rather than Emet-Selch being in love with Leuke he see's her as someone he can groom to be his eventual replacement. Death's apprentice. (Less love, still spiriting away to the Underworld)
In current time, Odette's eyes "started out" as an icy blue and as she grew into her abilities as a psychopmp one of them shifted to lavender. Her vision also altered -- I say she can see ghosts and other hidden things and I am beginning to think it's not so different from Hades' soul sight. Albeit a much weaker and less useful version, given the sundered state of it all?
I do think Leuce had soul sight, as well, likely part of the reason Hades picks her to work so closely with him. Mayhap it was weak and she spent most of her time trying to find ways to enhance it. As well as any work delegated to her by Emet-Selch, of course.
Personality wise I'm still rock tumbling her. I do think she and Emet have a very Uncle/Niece relationship, but also does that make sense for ancients?????? I'm gonna have to do more thinking and reading to really build this. I know I don't want her to be Odette But To The Left.