The National Archives is promoting Black History Month on its website: https://www.nationalarchives.gov.uk/black-history/
TNA's collections span 1,000 years of difference, debate and progress as they say:
"Created from the perspective of state and empire, we hold important records that bear witness to past injustice, and the long and continued fight for racial equality."
The National Archives are playing their part in finding greater ways to make their significant records more accessible.
Help with your research using The National Archives
The National Archives research guide on black British social and political history in the 20th century is a useful place to start.