hue vs polychromasia

hue

noun
  • A character; aspect. 

  • The characteristic related to the light frequency that appears in the color, for instance red, yellow, green, cyan, blue or magenta. 

  • A color, or shade of color; tint; dye. 

polychromasia

noun
  • A disorder in which there is an abnormally high number of red blood cells in the bloodstream as a result of their having been prematurely released from the bone marrow during blood formation. 

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