I believe it was Saul Alinksy who advised that we should use our enemies' tactics against them.
There really exists one way to stop the left's ahistorical colorizing of European history. We must make an attempt to white wash some of their sacred cows.
The way this would work would entail the anti-sjw political commentators to shamelessly start depict people like Martin Luther King, Malcom X, and even Barack Obama as white in their content.
Perhaps this would entail the photo-shopping of pictures, intentional modification of speech (i.e. saying "MLK was a prominent white civil rights leader for blacks"), all while the narrator speaks as if they don't know they're engaged in the white washing of black history.
It is very important that people readily understand that this would not be an attempt to obscure or even erase the truth. No, in fact, this will immediately put the left on the defensive. Moreover, this would show people the logical conclusion of the left's attempts to remove European's from their history.
They will suddenly have to realize that they cannot colorize historical figures that are tied to the ethnic heritage of one's country, without allowing us to whitewash their own deified darker skinned historical figures.
If I had the skills, the way I would go about this would be to make a semi-mockumentary esque film or youtube video on a prominent black figure. One that tells a true an unbiased story...except the person in question is white. And the narrator doesn't seem to notice they're depicting them this way.
I apologize if I rambled. But please give me your thoughts.