"White diaspora" is blowing my mind a bit. I think I would have been slapped by my social studies teachers if I ever used that phrase to describe colonialism. (I'm white, US)
Nice of you to assume that all white people had a chance to colonise (rather than be colonised and conquered by neighbouring nations on a regular basis). I'm not carrying the sins of the English-speaking (or otherwise formerly colonising) nations, so could the whites == colonialism assumption stay wherever other such weird assumptions belong.
European diaspora is an accepted term[1]. Yes there's a redirect, but the word "diaspora" is used in the very first paragraph. It's ok, Europeans are people too. There's nothing offensive about the term. Plenty of "colonials" were sentenced to transportation, they didn't choose it.
You can take solace in the fact that "whites" will never again command such societies in the future. The exaggerated "colonialism" narrative comes off as pining for a long-lost era of dominance, but in a socially acceptable way.
The era of Northern Europeans ("whites") dominating the globe is over forever, so no need to beat yourself up about it. Just letting you know that this extreme narrative is quite bizarre to non-Americans.