colour vs colouring

colour

adj

  • Australia, Canada, Ireland, New Zealand, South Africa, and UK standard spelling of color. 

noun

  • Australia, Canada, Ireland, New Zealand, South Africa, and UK standard spelling of color. 

verb

  • Australia, Canada, Ireland, New Zealand, South Africa, and UK standard spelling of color. 

colouring

adj

  • Of something that provides colour. 

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