where did the term blue collar and white collar originated
Blue-collar worker Historically the popularity of the color blue among manual labourers contrasts with the popularity of white dress shirts worn by people in office environments. The blue collar/white collar color scheme has socio-economic class connotations. However, this distinction has become blurred with the increasing importance of skilled labour, and the relative increase in low-paying white-collar jobs.
Origins of the blues Blues later adopted elements from the "Ethiopian (here, meaning "black") airs" of minstrel shows and Negro spirituals, including instrumental and harmonic accompaniment.[18] The style also was closely related to ragtime, which developed at about the same time, though the blues better preserved "the original melodic patterns of African music".[19]