In the congregation I was in, for 30 years, here in the UK, never in that time had any black JWs, or any other ethnic group.
Our sister congregation that shared our hall , had one black family, and that was only because they had moved up from London.
This even though there were many black families living in the area.
In Liverpool about 2-3 miles away, some congregation could be 20-25% coloured.
Also thinking about asemblies and conventions for our district, they were majority white.
Even though the district covered areas with large populations of coloured people.
Yet the church I now attend in the same area, we have many Nigerians, Ghanaians, Filipino, Chinese, Indians.
Probably nearly a third of the congregation.