Why Do We Say White Collar and Blue Collar?

How did blue collar, white collar (and pink collar!) end up in our lexicon, and what are the origins of their meanings?

The origins of white collar vs. blue collar - ADP ReThink Quarterly

White-Collar vs. Blue-Collar: What's the Difference?

Can You Wear a Contrast Collar Shirt Without Looking Gaudy?

What is the Difference Between Blue Collar and White Collar

Blue Collar vs. White Collar: Understanding the Differences • 7ESL

Ode: White Collar

Types of Unions, PDF, Blue Collar Worker

i.ytimg.com/vi/4vp0UnPencU/hq720.jpg?sqp=-oaymwEhC

LIMBO: Blue-Collar Roots, White-Collar Dreams - ppt download