mixed-race vs of color

mixed-race

adj
  • Having genetic characteristics of two or more different races. 

of color

adj
  • Nonwhite; of a race other than white, for example black. 

  • Belonging to a category of people with mixed black and white ancestry in the Americas in the 18th and early 19th centuries. 

How often have the words mixed-race and of color occurred in a corpus of books? (source: Google Ngram Viewer )