the meaning the colour pink holds is obvious: since pink is only used in alnst as mizi's hair colour, it represents the fantasy she creates and lives in, and by extension, the fantasy people see in her.
in round 1, a pink bubble surrounds mizisua as they perform. this stage performance is the one they've dreamed of since they were young, and both of them play the part of the fantasy until it inevitably ends, when the bubble pops for good. sua dies, and mizi's unable to keep up her innocent facade, as represented by the pink tint disappearing.
of course, this doesn't mean pink disappears entirely. mizi's facade is broken down slowly over the course of the series, as this life long act is not just something that can be instantly resolved.
hair length represents attachments: her hair gets shot off as she resolves herself to move on past her grief for sua and take action - just like hyuna does (note the fallacy here). till still holds onto her as his only comfort, and it's represented by just her hair because he's only attached to the fantasy of her that he's constructed for himself, not for who mizi actually is. similarly, pink tints his scenes when he uses fantasy and the image of her to cope.
in the end, even with her hair cut off, mizi still chooses to play dumb. in other words, she's not facing a full picture of reality, but escaping to the fantasy that her own facade provides - a comforting naive innocence, where she doesn't need to confront the consequences to her own inaction. she still pretends to be a naive girl, because it's her only coping mechanism and how she navigates the world. but a lifetime of guilt catches up to her, catalysed by the death of the last of her friends, and famously she crashes the fuck out.
as she faces reality, her pink grows washed out against the red of her crisis. the moment she saves till is arguably one of the moments where she is most "herself" - there's no pretence or motive to her actions other than needing to save the last remaining member of her family.
the last traces of mizi's pink hair are then hidden by a long, black wig, as she essentially becomes a widow, living life in continous mourning. but some of it still shows through, and it becomes the only colour other than black and red that defines her after she's made into Witch.
isn't solely blaming herself for everything, tying herself to it, and not allowing herself to move on just as juvenile as pretending she doesn't know anything? isn't she just refusing to face the full truth again? she escapes one fantasy just to live in another, but this one is of an ugly nightmare instead of a beautiful dream.
until the very end, she's still living in perpetual performance, acting her assigned part, wilfully playing pretend. from girl to bride to witch, there is no respite. to be a woman - to embody pink - is to be what others want from you.














