Saffron the Yellow Fairy (Rainbow Magic #3)

Rachel and Kirsty and their families meet on the ferry, on the way to Rainspell Island for a holiday. The girls are sure they'll have lots of adventures together, especially as Rainspell Island seems almost magical. But when they go on a hunt, the first day, for the end of a rainbow neither of them really expects for find a pot at the end of it. Especially not one with a ruby red fairy trapped inside! And so begin Rachel and Kirsty's adventure to find the seven Rainbow Fairies, banished by the evil Jack Frost, and restore colour to Fairyland.