Wolf Hall has some excellent acting from stars like Mark Rylance and Damian Lewis, and I love the attention to detail with the period costumes and locations, so why then not respect the ethnicity of the historic figures? Elizabeth Seymour was not black, it is just ridiculous having a black sister (Elizabeth) standing next to a white sister (Jane Seymour), this totally breaks the realism.
I don't expect minor things (like the bad teeth people had during that period) to be reproduced, but ethnicity is as obvious as costumes and changing this totally breaks emersion. Just like someone suddenly appearing in jeans and a t-shirt would.
In the BBC series "A suitable boy" the BBC trumpeted the fact that they used an all Asian cast to play the Asian characters - no white actors.
Coco - played by all Hispanic actors.
Blank Panther - all African characters were played by black actors.
Prey - Only Native American actors were chosen by Disney to play the Native American characters.
Shogun - All Japanese characters were played by Japanese actors (and spoke Japanese).
In all of the above the race of the non-white characters were respected (which I agree with) - all I ask is that the same respect should be shown to white people. We can then enjoy authentic and realistic period dramas without the jarring and immersion breaking casting seen in a lot of modern period dramas (when set in Europe) today.