white-collar (adj.)

by 1911, perhaps 1909, from white (adj.) + collar (n.).

The white collar men are your clerks; they are your bookkeepers, your cashiers, your office men. We call them the 'white collar men' in order to distinguish them from the men who work with uniform and overalls and carry the dinner pails. The boys over on the West side got that name for them. It was supposed to be something a little better than they were. [Malcolm McDowell, quoted in Chicago Commerce, June 12, 1914]

White-collar crime attested by 1957 (there is a white-collar criminaloids from 1934).