Sunny has an amazing discovery while portal jumping through Rainbow World: she can collect liquid rainbow and use it to color and create new outfits! She wants everyone to try, but it’s almost time for the Color Block Party, and they need to get back to Rainbow High. Poppy and Ruby decide to stay in the portal with Sunny, and they’re having so much fun creating new, colorful looks! But oh no! The rainbow portal is starting to close! Will the girls find a way out and join their friends for the party?