Make a colour thesaurus and retell the story
In the story there are lots of different coloured crayons.
Can you find synonyms for different colours? (e.g. Red = crimson, maroon, rose, cherry). Make a colour thesaurus using the new words.
When you have made your colour thesaurus, you could retell the story using the synonyms you have thought of for the colour crayons.
Remember to use a strong, performing voice when retelling your story, and use some expression when the characters are talking.