achromasia vs pallor

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. 

pallor

noun
  • Paleness; want of color; pallidity; wanness. 

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