I can kinda see the "white-collar" image, with formal dress shirts, but "blue-collar" is not intuitive to me, and Dictionary.com and Etymonline are not helpful as to the reason for the color choice. Does anyone know the reason for the color blue in "blue-collar"?
closed as general reference by Alenanno, Daniel δ, kiamlaluno, waiwai933♦ Jul 16 '11 at 17:52
This question is too basic; it can be definitively and permanently answered by a single link to a standard internet reference source designed specifically to find that type of information. See the FAQ for guidance on how to improve it.
"Blue collar" is a reference to the overalls worn by workers in jobs which require working with tools.
The overalls protect their clothing.