alternate_costume - None of the characters are wearing their "official" clothing, though in most cases the basic color scheme is still there (Alice excluded).
adapted_costume - Depends on the portrayal, but I'd lean towards no. The ones where you could apply that to easier typically have elements of them integrated into the dress somehow. (Youmu and Nitori being prime examples, and Momiji, Tenshi, Yuuka, Tewi, Murasa to lesser extents.)