purpuric vs violetish

purpuric

adj
  • purple in colour; derived from or forming a substance which is purple; especially 

  • Pertaining to or affected with purpura (skin discoloration from blood inside it). 

  • Derived from or forming purpuric acid. 

violetish

adj
  • Somewhat violet (in colour). 

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