A blue-collar worker is a working class person who performs manual labor. Blue-collar work may involve skilled or unskilled labor. The type of work may involving manufacturing, warehousing, mining, excavation, electricity generation and power plant operations, electrical construction and maintenance, custodial work, farming, commercial fishing, logging, landscaping, pest control, food processing, oil field work, waste collection and disposal, recycling, construction, maintenance, shipping, driving, trucking, and many other types of physical work. Blue-collar work often involves something being physically built or maintained. In contrast, the white-collar worker typically performs work in an office environment and may involve sitting at a computer or desk. A third type of work is a service worker (pink collar) whose labor is related to customer interaction, entertainment, sales or other service-oriented work. Many occupations blend blue, white, or pink-collar work and are often paid hourly wage-labor, although some professionals may be paid by the project or salaried. There are a wide range of payscales for such work depending upon field of specialty and experience. Origin of term The term blue collar was first used in reference to trades jobs in 1924, in an Alden, Iowa newspaper. The phrase stems from the image of manual workers wearing blue denim or chambray shirts as part of their uniforms. Industrial and manual workers often wear durable canvas or cotton clothing that may be soiled during the course of their work. Navy and light blue colors conceal potential dirt or grease on the worker's clothing, helping them to appear cleaner. For the same reason, blue is a popular color for boilersuits which protect workers' clothing. Some blue collar workers have uniforms with the name of the business and/or the individual's name embroidered or printed on it. Historically, the popularity of the colour blue among manual labourers contrasts with the popularity of white dress shirts worn by people in office environments. The blue collar/white collar colour scheme has socio-economic class connotations. However, this distinction has become blurred with the increasing importance of skilled labor, and the relative increase in low-paying white-collar jobs. Educational requirements Since many blue-collar jobs consist of mainly manual labor, educational requirements for workers are typically lower than those of white-collar workers. Often, not even a high school diploma is required, and many of the skills required for blue-collar jobs are learned by the employee while working. In higher level blue collar jobs, such as becoming an electrician