Jill's hair?

Pretty much from the comic, where it is blue. If you want to apply logic to Bilal's work, you will probably end up with a headache (apart from his earlier collaborations with Pierre Christin). His is more of a dream world.

"Fortunately, Ah keep mah feathers numbered for just such an emergency!"

Her hair stressed me out too. But I guess she was supposed to have a distinctly non-human appearance. In the original trailer from 2001 (on the DVD extras ) Jill is played by a different actress and her hair, while still blue, is longer and softer looking.