burnt sienna vs horse chestnut

burnt sienna

noun
  • dark reddish brown colour, like that of roasted sienna. 

adj
  • Of a dark reddish brown colour, like that of roasted sienna. 

horse chestnut

noun
  • The large nutlike seed of these trees. 

  • Any of several tree species of genus Aesculus, especially Aesculus hippocastanum, common in temperate northern hemisphere. 

How often have the words burnt sienna and horse chestnut occurred in a corpus of books? (source: Google Ngram Viewer )