blue, white and pink

     Blue, white and pink are the colors of collars worn by workers in the United States. People who work with their hands, or with things, are called blue-collar workers, from the traditional blue shirt worn by workmen.
      People who work with pencils, pens, paper, typewriters, computers, calculators and adding machines are called white collar workers, because of the white shirt traditionally worn with a man's dress or business suit. The people who build or repair the machines used by white-collar workers may be blue-collar workers.
     Women who work in jobs that are usually done by women--nurses, day care workers-- are often called "pink collar" workers, although this term is not "official".