Elly's hair is a bright red color and her wings are a blood red color, there not like this for no reason...it represents something. The battle you must take to gain freedom.
Elly wishes freedom was a given right but the truth was everyone had to fight for their freedom in there own way.
Wither it be a child proving to their parents they can make it into the world on their own, a slave fighting for freedom from it's master...or an angel, workign to pull themselves away from the heavenly host and to have a will of their own.
I like to think that Elly's wings and hair are stained red by the blood that's had to be split over the course of history for people to gain the freedom that she represents.
That bother her hair and wing's used to be as pure white as freshly fallen snow. But Elly doesn't wish for pureness to come bzack into her wings, but wears the color happily. Showing it off to the world with pride.