lilac vs mauve

lilac

adj
  • Having a pale purple colour. 

noun
  • A flower of the lilac shrub. 

  • A pale purple color, the color of some lilac flowers. 

  • A large shrub of the genus Syringa, especially Syringa vulgaris, bearing white, pale-pink, or purple flowers. 

mauve

adj
  • Having a pale purple colour. 

noun
  • The colour of this dye; a pale purple or violet colour. 

  • A bright purple synthetic dye. 

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