The mangao or 'dragon' jacket was based on Ming dynasty styles of dress, with wide sleeves. They continued to be worn by Han Chinese women, who did not wear the Manchu robes of the succeeding Qing dynasty. This example is unusual as it dates from the late 18th - early 19th century.
Red is associated with family celebrations, especially weddings, births and birthdays, which is most appropriate as the word for red, fu, is a pun on the word for happiness.
Compare the similar wedding robe from the Hong Kong Museum of Art, illustrated by V.M. Garrett, Chinese Clothing: An Illustrated Guide, New York, 1994, pl. 37.