You will need:
A large tray (or washing up bowl), some water, grass, flowers or mud! An old white or cream t-shirt/vest/top. Some string. A saucepan, some salt (1/4 cup). A hammer or food processor.
Cut 3 long pieces of string. Screw your top into a ball and use the 3 pieces of string to tie it up. Tie it as tightly as you can.
Pop your top into a saucepan and cover with water. Now add 1/4 cup of salt (or vinegar) and simmer on a low heat for 1 hour. You might ask a grown up to keep an eye on it for you so that you can get on with the other tasks!
Now collect some flowers (or raid the cupboards!). We have some suggestions:
Blue: Grape hyacinths
Yellow: Dandelions and/or daffodils (or tumeric)
Red: Lavender or avocado skins
Green: grass, spinach or green seaweed
Put your finds into a bowl (you need to try to have the bowl at least 1/3 full) and then bash with a hammer (or pop into a food processor). Cover with water (about double the amount of the flowers/fruit/finds) in a saucepan and boil for about 40 mins (just enough time to have a good play!).
Now you've done the hard work and its time for the good part! Pop the flower liquid into a bowl (outside is better as it will cool down faster!). Take out the top from the other saucepan and rinse it under cold water. The ring it out. Take it to the bowl outside and give it a good stir. Then leave overnight.
Take it out and leave to dry in the sunshine (or you can ask a grown up to dry it on a plate in the microwave for 2 mins and then pop it over the top of a towel on a radiator).