Duo Halloween Costume: Elsa and Anna From "Frozen" Dressing up as sisters Anna and Elsa from "Frozen" is a no-brainer for Disney fans. Bring along a tiny Olaf plush to really knock this duo costume out of the park. What to wear for Elsa: A sparkly blue dress and blond wig styled into a long braid. What to wear for Anna: A red wig with two plaits, plus a blue skirt, black vest, and pink cape. Image Source: Disney