citrus fruit vs yellow-red

citrus fruit

noun

  • Any of the fruits in the common genus Citrus of flowering plants in the family Rutaceae. 

yellow-red

noun

  • The colour orange. 

adj

  • Consisting of yellow and red colours individually. 

  • yellow-red 

  • Of a colour between yellow and red; orange. 

How often have the words citrus fruit and yellow-red occurred in a corpus of books? (source: Google Ngram Viewer )