If a sprite has any pixels that are 0,0,0 in colour and the actor using those sprites suffers an ice death, the black pixels get translated to a colour that, in my opinion, is too bright.
e.g. this guy:

ends up looking like this when he is frozen:

His trousers, clipboard, edge of his shoes and hair have become very light in colour and it gives the sprite an awkward semi-negative-colour kind of effect.
I'm not convinced it was always like this - but I'm also not convinced that it wasn't.
Would there be any way to ensure that true black areas explicitly get translated to something suitably dark but still consistent with the icy palette? I know that true black isn't a good choice for sprites anyway, but sprites with black areas are out there.