lilac vs petunia

lilac

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

  • A flower of the lilac shrub. 

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

adj
  • Having a pale purple colour. 

petunia

noun
  • A dark purple colour, like that of some petunia flowers. 

  • Any of the flowering plants of genus Petunia, of which most garden varieties are hybrids. 

  • a homosexual 

adj
  • Of a dark purple colour, like that of some petunia flowers. 

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