I agree with the sibling's point: MLK's ideals transcend ideology. He understood that all men of all colors were equal before God; a belief which he instilled in his movement. He did not play the motte-and-bailey game of "some are more equal than others", that was so popular last decade.
Calling MLK's values "colorblindness" in the way of "racial liberation" is the kind of double-speak the GP criticizes. Language that distances everyone from the capital-T Truth that MLK knew and died for, in favor of small truths that pretend to unite but actually divide.