Mix the first 5 ingredients together in a pot (all but the food colouring).
Cook on medium/low heat stirring until it becomes a play-dough like consistency.
Turn the dough out on some baking paper. When it's cool enough to handle, knead it a few times until smooth.
Divide the dough into 6 balls, or into the number of colours you will be colouring the dough.
Pop on you kitchen gloves and add a few drops of food colouring to each ball, knead until the colour is well mixed through.
Wrap each ball in cling wrap and store in an airtight container. These can last for months when stored properly.