perse vs purpure

perse

adj
  • Dark greyish blue or purple. 

noun
  • A dark blue-gray colour. 

  • A cloth of this colour. 

purpure

adj
  • In blazon, of the colour purple. 

noun
  • A purple colour on a coat of arms, represented in engraving by diagonal parallel lines 45 degrees clockwise. 

  • purpure 

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