Yobo, Yak and Vic are Nigerians though dark, and the article is about South Africans...you need to pay more attention in geography .
Personally I'm amazed that there have been as many as four previously....I can't think of any .
Edit: Found this..."After World War Two, a flurry of South African footballers left to play in England, almost all of them white, who were members of the racially-segregated national side."
"Bill Perry played for England and scored the winning goal in the famous 'Matthews' FA Cup final of 1953 when Blackpool came from behind to beat Bolton Wanderers 4-3."
So that's one.
"South African Albert Johanneson was the first black player to play in a FA Cup final for Leeds United in 1965."
Two.