I remember seeing an anime movie with a forest spirit who was almost like water, I don't know what its called?

To be honest I never actually saw it, I thought maybe that it was
Princess Mononoke but I just watching it and didn't have the character
that I'm seeing in my minds eye. I was similar in the feel of the
movie so I thought it was by the same creator, but I cant find it
their ether. The spirit was a girl no doubt, she was a teal color of
greens and blues, he hair flowed like water as she moved about a
forest. I think I saw it during a commercial I guess I just want to
know if it was something I really saw or my mind just fabricated.