Áo dài the "ngũ thân" as a modern dress in the 1920s and 1930s. The updated look was promoted by the artists and magazines of Tự Lực văn đoàn (Self-Reliant Literary Group) as a national costume for the modern era. In the 1950s, Saigon designers tightened the fit to produce the version worn by Vietnamese women today. The dress was extremely popular in South Vietnam in the 1960s and early 1970s. On Tết and other occasions, Vietnamese men may wear an "áo gấm" (brocade robe), a version of the ao dai made of thicker fabric. Academic commentary on the ao dai emphasizes
The dress first large-scale scientific study on the dress was published in "Current Biology" three months after the image went viral. The study, which involved 1,400 respondents, found that 57% saw the dress as blue and black; 30% saw it as white and gold; 11% saw it as blue and brown; and 10% could switch between any of the colour combinations. A small number saw it as blue and gold. Women and older people disproportionately saw the dress as white and gold. The researchers further found that if the dress was shown in artificial yellow-coloured lighting almost all respondents saw the dress