"John Olsen leaves a space but true to form, he saw to it that it would be filled with colour and light as bright as that twinkle in his eye," Mr Albanese said at the service in Sydney on Monday.

Olsen's career spanned nearly seven decades and he died on April 11, aged 95.

He won the Wynne, Sulman and Archibald Prizes and was awarded the Order of Australia and an OBE.

Australia's art world is paying tribute to the painter, with Wendy Whiteley, Ken Done and Ben Quilty among those in the crowd at the Art Gallery of NSW.

Daughter Louise Olsen remembered how their family lived in a mud brick house with paintings by some of Australia's greatest artists on the wall, and she felt proud that her father was unlike any other.

Tim Olsen said his father showed them that a different world was possible.

"We want to keep that vision and that dream alive... especially in times like today, in such a difficult world, we have to take refuge in beauty."

Master of ceremonies Michael Yabsley said Olsen, who lived in Newcastle until moving to Sydney at age seven, brought untold joy to many, and had charisma by the truckload even in his later years.

"When it came to lighting up a room he was in a class of his own - remarkably, in the twilight of his life, John was still in the prime of his life," he said.

He remembered the artist as a bon vivant, a cook, philanthropist, teacher, mentor, lover of literature, and businessman too.

"The great man would say the only embellishment to an outstanding piece of art should be a red dot."

The Sydney Art Quartet played some of Olsen's favourite pieces of music, before musician William Barton performed his piece Spirit of the Landscape for voice and didgeridoo.

"Now Uncle John is up there painting those big dreaming stories too with those elders of our landscape and our mother country... his paintbrush was his message stick," Mr Barton said.