The practice of the Australian Chief of Naval Staff and Chief of Navy using green ink to annotate and sign administrative correspondence stems from a Royal Navy tradition established in the early twentieth century.

The origin of this custom may date from Admiral Jackie Fisher’s second and brief appointment as the First Sea Lord at the British Admiralty at the start of the First World War. On discovering that the First Lord of the Admiralty, Mr Winston Churchill, had ‘monopolised the red pencils and ink for his minutes, Fisher seized the green and used that colour exclusively’.

The use of green ink by successive First Sea Lords, chiefs of Naval Staff and chiefs of Navy in the Royal Navy and Royal Australian Navy took hold, becoming an enduring tradition. In today's digital age, the use of green font routinely substitutes for the more traditional green pen.