Visitors colour in one of six animal templates and put it in a scanner. A life-like 3D version is then printed and put into a glass tank to "swim".
The initiative was inspired by similar attractions in the UK and Turkey.
Colouring-in brand Crayola had sponsored Amazing Creations.
Kelly Tarlton's marketing manager Claire Wheeler said the aquarium had been pleased with visitors' response.
"It's been really cool to see people's creativity. People's patriotism has definitely come out."
But it's not just fun and games. Amazing Creations had an important conservation message.
Wheeler told the Herald on Sunday that staff hoped people would "fall in love with these amazing creatures, see them in new ways and then want to protect them".
"Some of the world's most amazing, colourful, exotic and exciting fish live in coral reefs, which are actually quite a vulnerable part of the ocean that need support."
The exhibit, which runs until January 30, had been as popular with adults as kids, Wheeler said.
"You'd think it would just be for kids but everybody loves colouring-in."
Kelly Tarlton's general manager Tim Keeling agreed.
"It's a great chance for the entire family to use their imagination and get the creative juices flowing."
The exhibit is free with entry to the aquarium and is open 9am to 4.30pm.