A tactile way to explore 5 of the 7 rainbow colours, with purple substituted for indigo & violet, is through rice!
Have fun with the colouring process where children make their own dyed rice using tubs or zip-lock bags.
About rainbows - wikipedia
The Rainbow storybook by Felicia Law - on amazon.co.uk
![](http://www.silkysteps.com/resources-for-play/Activities/Recipes-play/coloured-rice-recipe-for-play/coloured-rice-activity.jpg)