I find your definition of "insulting" really confusing, as pretty much all "white collar jobs" are "I sit on my butt all day and think lazily about things with very little pressure" jobs. They push paper and write reports on things, maybe doing some annoying math at times, but the entire concept of a "high pressure" job with "consequences for error" seems entirely at odds with white collar, and I'd personally have expected people who actually do something important on a daily basis (unlike, for example, me) might would find being categorized as "white collar" insulting?

It's equally insulting to insinuate that some blue collar jobs don't also require more education and have much higher pressure and consequences for error than many white collar jobs.

There are many blue collar jobs that require a lot of education and the consequences of errors is loss of life.

Did you read the Wikipedia article? Grey collar is work that takes both intellectual and physical skill. It even includes surgery as grey collar. Thinking white collar indicates more education and pressure is the issue. There's white collar jobs that can be done by high school graduates, and blue collar jobs where life and death are literally a split second away most of the time.