The Marge Simpson costume is a very popular costume based on the character from the animated comedy series The Simpsons. It is mostly a costume that women would wear. It consists of a tall blue wig, a green dress, a necklace of red beads and red shoes. Wearing a Marge Simpson mask or using make-up to color your skin yellow is optional.
See the article on Marge Simpson on Fandom's Simpsons wiki.