Any group that can be grouped together into a small group is a minority. Don't have to have a separate skin colour for that.

Polish people in Germany are a minority. Turkish people in Austria are a minority. Protestants are a minority in the Republic of Ireland. Gay and trans people are a minority.

The defining factors of a minority in regards to this kind of debates are:

• It's a category that can be used to group people together. The group doesn't have to be internally consistent but are lumped into this group from the outside (e.g. all "foreigners" can be lumped into one group, even though these people are from all sorts of different countries and backgrounds and might not even interact with each other all that much. Like, for example, a white Nazi from Russia is just as much a foreigner as a black hippie from Ghana, even though these two people really have nothing in common.)
• The resulting group is smaller than the majority group.
• Resulting from these facts, the larger majority has the political power to govern the minority group via laws and executive even against the will of the minority group (and often without even understanding the minority group)
• And resulting from that fact, there needs to be some kind of protection against misgovernment against that minority group that isn't large enough to effect actual political change themselves.