I love both Alex and Lynn's and Meav's most because as former members the color choices represented the signature color they wore or the color which they first started out in as CW (Lynn for instance).
Meav wore this color especially during ACC but I predict she would of worn that color had she been part of SFTH.
My most favorite are the middle blue and black dresses for Amazing Grace, Orinoco Flow those were the best almost Frozen power of CW look at Meav with that train or Lynn style like that!