At a press conference in New York in 1977. Photo / AP
"Ever quick-witted and direct, we looked forward to her visits from Norfolk Island and the arrival of each new manuscript delivered in hard copy in custom-made maroon manuscript boxes inscribed with her name," Ms Martyn said.
"The world is a less colourful place without Col."
Ms McCullough wrote 25 novels during her career with the last, Bittersweet, published in 2013.
Before becoming a best selling author she established neurophysiology department at the Royal North Shore Hospital in Sydney and spent a decade as a researcher at Yale Medical School in the US.
From politicians to authors, tributes have flowed for Ms McCullough, who is survived by her husband Ric Robinson.
Prime Minister Tony Abbott said Ms McCullough had enthralled readers for decades.
"Colleen McCullough was a unique Australian personality and Norfolk Island's most famous resident," he said in a statement.
"She will be missed."
Opposition Leader Bill Shorten said Ms McCullough's impulse purchase of a typewriter had immeasurably enriched the literary landscape of Australia and the world.
"Colleen has written her final word but she lives on in bookshelves and libraries around the world - and in the hearts of all who loved her," he said.
Fellow Australian author Tara Moss described Ms McCullough as irreplaceable.
"So sad to hear of the passing of Colleen McCullough. She was fierce, funny and so supportive of other writers. Irreplaceable. RIP Colleen," she tweeted.
Random House Books tweeted that Ms McCullough's contribution to storytelling was the stuff of legends while federal MP Alex Hawke said her Masters of Rome series was world-leading historical fiction.
- AAP