perse vs purpurate

perse

adj
  • Dark greyish blue or purple. 

noun
  • A dark blue-gray colour. 

  • A cloth of this colour. 

purpurate

adj
  • Of a purple colour. 

noun
  • A salt of purpuric acid. 

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