piebald vs unflecked

piebald

noun
  • An animal with piebald coloration. 

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

  • Of mixed character, heterogeneous. 

unflecked

adj
  • Not marked with flecks. 

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