multiethnic vs polychromate

multiethnic

adj
  • Of, pertaining to, or consisting of several ethnic groups. 

noun
  • A member of more than one ethnic group. 

polychromate

adj
  • Composed of many colours 

noun
  • A salt or ion composed of multiple chromate groups 

How often have the words multiethnic and polychromate occurred in a corpus of books? (source: Google Ngram Viewer )