purpure vs purpureous

purpure

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

  • purpure 

adj
  • In blazon, of the colour purple. 

purpureous

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