dirty blonde vs fairheaded

dirty blonde

adj

  • Of a dark blonde colour/color bordering on light brown. 

noun

  • A dark shade of blonde, bordering on light brown. 

  • A person with dark blonde hair. 

fairheaded

adj

  • Blond or blonde. 

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