Bert Trautmann was still playing for Man City in 1964 and was then probably the best-known footballer from outside the shores of the UK and Ireland playing in the First Division (and I'm not counting players born to services personnel). The most exotic that Forest ever got during that period was Flip Le Flem from Guernsey.

In terms of home-grown black players, don't forget Charlie Williams who played regularly for Doncaster Rovers during the late 1950s.

And the first black player thought to have captained an English team was the late Pedro Richards of Notts County (probably also the only captain to have spent his childhood in a rural village in the Basque country - see http://www.markhodkinson.com/pages/journalism_pedro_richards.htm for the full and very sad story of Pedro's life once he retired from football).