achromasia vs pallidness

achromasia

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

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

pallidness

noun
  • The characteristic of being pallid. 

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