Blue-collar refers to all wage earners who are mainly manual workers, such as general industrial and mining workers, agricultural workers, construction workers, dockers, warehouse managers, etc. The work clothes they wear at work are usually blue, hence the name.
Pink collar defined by sociologists usually refers to women engaged in auxiliary work. For example, one of the most representative pink collar jobs is secretary, and there are also data entry clerks, shop assistants, teachers or other educational jobs. Other jobs include nursing and cleaning.
Gray collar: gray collar, originally refers to the skilled workers responsible for the maintenance of electrical appliances, sewers and machinery. These workers often appear in gray overalls, hence the name of this profession. Now the scope of gray collar has been extended to electronic engineers, software development engineers, decoration design engineers, drawing engineers, spraying engineers and so on. Compared with white-collar workers and blue-collar workers, "gray-collar" professionals should not only have good theoretical literacy, but also have practical ability. They are compound and practical talents.
Jinling, some of them are company managers, such as CEO, CFO or COO. Some advanced knowledge practitioners are engineers, lawyers, analysts and forecasters in various industries, senior editors, programmers, interpreters and so on.
That's about it.