The colourful project was instigated by the Catholic Schools Office education officer Kim Moroney, who wrote to primary school principals informing them of an unfolding story out of a town in northern Italy, Reggio Emilia.
"The children are using drawings to convey the message that the virus would be defeated, that everything will be fine, the rainbow will win," Ms Moroney wrote.
Principals were encouraged to share the story of the children in Reggio Emilia with their students and provide opportunities for them to create rainbows.
The principal of St Patrick's Primary School, Swansea, Peter Green, took up the invitation saying he believes there is a need to balance "negative messages being shared about the pandemic in media and on social media”.
"It's important that we're doing what we can to support children's mental health, particularly at this point,” he said. “Creating the rainbows is one small way we can do this, as it is a story of hope that the children can relate to."
Sophie Hill, who is in Year 2 at St Patrick's Primary School, said she enjoyed painting her rainbow artwork.
"The rainbow means things will get better, quicker. We're all in this together to make people happier," said Sophie.
Ms Moroney is in the process of co-ordinating photos of artworks to be sent to contacts in Reggio Emilia.