Clearly unrelated to our current topic of the human body, we nonetheless had great fun with this experiment. When researching solutions to bring colour back to the planet and defeat the 'dulling', we tried to create a walking rainbow with just 3 primary colours, 6 jars and 6 sheets of kitchen roll. The whole class (adults too!) were completely mesmerised by the process. We couldn't believe how quickly the water travelled up the paper towel and how magical it was to watch the colours mix together.