The music video for "Twinkle" isn't out yet but you can have a preview of Taeyeon, Tiffany and Seohyun nails.
Seohyun - white base with rhinestones flowers. I love it!
I was surprised by her nails since she usually have very natural nails.
Taeyeon - deep berry creme with a silver accent on her left ring finger.
Tiffany - white french with lots of pearls and rhinestones.