lilac vs umber

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. 

umber

adj
  • Of a reddish brown colour, like that of the pigment. 

verb
  • To give a reddish-brown colour to. 

noun
  • A dusky brown African wading bird (Scopus umbretta) allied to the shoebill and herons; a hamerkop. 

  • A grayling. 

  • A brown clay, somewhat darker than ochre, which contains iron and manganese oxides. 

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