Is it solely a matter of self-identification?

Lee Jasper (Co-Chair of BARAC & National Black Members Officer for Respect Party UK)  draws attention to an article by former Independent editor Professor Ian Hargreaves "NUJ in ethnic diversity warning for UK journalism" http://www.thedrum.com/news/2013/03/27/former-independent-editor-professor-ian-hargreaves-and-nuj-ethnic-diversity-warning

When Lee Jasper talks about people being "black" and "white" what definition is he using?

Is it solely a matter of self-identification?

We know the bureaucratic nightmare the South African governments 1948 to 1994 engendered when trying to define who was black and who was white.  Despite all their efforts they were unable to come up with a scientific basis to race analysis.  Ultimately it became an entirely arbitrary assessment, farcical but also tragic, and supported by a system of pass books and kafkaesque "race" procedures.

Therefore perhaps Lee Jasper could enlighten us.  Who are the black people and who are the white people he talks about?  Unless that question can be answered the whole theory of race equality and multiculturalism must collapse under its own contradictions.