chromaticity vs coloring

chromaticity

noun
  • An objective specification of the quality of a colour, regardless of its luminance. 

coloring

noun
  • Any substance used to give color. 

  • A disguise or discoloration. 

  • The appearance as to color. 

  • An assignment of a color to each vertex of a graph such that no two vertices connected by an edge are given the same color. 

  • An act or process which applies color. 

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