Starship Foundation chief executive Brad Clark said it was about making parents and children as comfortable as possible.
"We wanted to make the plane look friendly for kids in what must be a scary time," he said.
"The design has done this ... they have captured the essence of Starship."
Starship paediatric intensive care doctor Dr David Buckley, who was involved in the management of the medical flight team, said it was a "beautiful, state-of-the-art new plane" that would enable sick children to be transported safely and quickly.
The air ambulance, which is part of a 24-hour, seven-day-a-week service, flies around the country and to places in the Pacific and Australia.
It is used to retrieve babies and children who are sick or injured for treatment in the hospital's paediatric or neonatal intensive care units.
The on-board specialists, who include specially trained flight nurses and doctors, work to stabilise the child before bringing them on board for transport.
Paediatric intensive care unit nurse Di Fuller has been on the flight team for 14 years.
"It's not just a taxi service," she said. "It is intensive care in the air ... you need to concentrate and be on the ball all the time."