Sostek, Anya. It's not just blue or white collar anymore as consultants labels for new jobs to the pallette. 匹兹堡邮报. 2006-08-11 [2018-04-14]. （原始内容存档于2018-04-14）. The least defined term of all seems to be grey collar, which can refer to those working well into their 60s, because they can't afford to retire, or to an underemployed white collar worker, such as someone with a bachelor's degree in English literature working as a customer service representative.