How were black people represented through 'Sapphire'?

Throughout 'Sapphire' there is a very strong racist view of black people throughout. This is clearly shown by the use of the quote, "she died because she was black" this gives the immediate racist view as it connotes the way that Britain have a very poor view of Black people in Britain. Another sense of racism shown from the film would be where the detective says "nice enough for a coloured" which shows how he thinks yeah for a black person its okay but if it was a white girl then it would be disgusting as a white girl is so much better then what they believe a black women is so therefore black people can wear such horrid clothes. However this is the case  I believe there is what appears to be a racial solution through the film, this comes particularly through the brother and the fact that he is presented as a smart respectful man as they would expect a typical white man would be, this is shown typically towards the end of the film where the brother and the more racist of the two detectives shake hands showing the mutual respect they have now between black and white.