Dunno how it is in Germany but quite a few of my non white friends wound up in the Canadian Army.
I don't know why immigration is brought up in this conversation at all.
There are a lot of non-white citizens of Canada (and Germany) whereas the comment you’re replying to is about non-citizens. Also Canada hasn’t had conscription for a long time as far as I know, the friends you refer to were volunteers.
It is about citizenship, not race.