piebald vs polychromate

piebald

adj
  • Spotted or blotched, especially in black and white. 

  • Of mixed character, heterogeneous. 

noun
  • An animal with piebald coloration. 

polychromate

adj
  • Composed of many colours 

noun
  • A salt or ion composed of multiple chromate groups 

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