Nanny Mihi's grandchildren come to stay during the school holidays. Each day, she sends them out to collect objects of a different colour. They scour the local beach collecting shells, flowers, seaweed and beach detritus left by humans, all the time asking, 'why?'.

By the week's end they have a collection of coloured items for a beach rainbow.

Tracy Duncan's revamped artwork and Melanie's enduring story ensure that once again children's imaginations will be captured. It is hard to resist Nanny's charm and patience with her mokopuna, who are keen to race to their outcome but upset to see it so quickly taken away by the sea.

Nanny teaches the children patience, creativity, connection to nature, and that sometimes the best things are those things we cannot hold on to. The text includes te Reo throughout, for which translations are provided.