achromasia vs paleness

achromasia

noun
  • Absence of normal skin pigmentation (from bruising, stress or disease); pallor or achromia. 

  • The inability of a cell or tissue to be stained. 

paleness

noun
  • The condition or degree of being pale or of lacking color. 

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