Caucasian vs melanin-challenged

Caucasian

adj
  • Of a person: having a white complexion and European ancestry; white. 

  • Of or relating to the Caucasus region or its culture, languages, and people. 

noun
  • A white person. 

  • A group of languages spoken in the Caucasus region. 

  • A native or inhabitant of the Caucasus. 

  • Synonym of White Russian (“a cocktail consisting of coffee liqueur, milk, and vodka”) 

melanin-challenged

adj
  • white; having white skin or belonging to the white culture; not black 

How often have the words Caucasian and melanin-challenged occurred in a corpus of books? (source: Google Ngram Viewer )