“visible minority”

While learning about multiculturalism in Canada, I often hear a term called “visible minority”

If I translated into Japanese, would it be 可視マイノリティ or 見えるマイノリティ? ... both suck...

According to Canafian government, it is defined as

“persons, other than aboriginal peoples, who are non-Caucasian in race or non-white in colour”

which means Chinese, Indians, Philippines, or Soudi Arabians etc, living in Canada.

The question I came up was why we have to call them “visible minority” instead of just minority? What’s the difference? 

I was thinking like thereight be an assumption that minority should be invisible, but in Canadian situation mantioning about race, it still doesn’t make sense to me. I gotta ask it to my teacher today.