Rainbow Walking Water

Rainbow walking water creates excitement and critical thinking skills in kids!

How does it work?

It starts with primary coloured water ‘walking’ (dripping) into empty jars. The primary colours mix to make a rainbow effect. This experiment was a relatively easy activity for ages 3-6 to do themselves. However, although the experiment starts off quickly, it takes at 2 days to get the best results. If you plan on doing this activity leave it somewhere it can be stored for that long.

To extend young children further you can start by predicting or hypothesising what might happen to the yellow, blue and red water colours. This will lead further into why there are empty jars. Don’t be afraid to use big words because you are building practice in vocabulary.

Here’s what you will need:

  1. 6 x glass jars (or clear plastic cups)
  2. spoon
  3. yellow, blue and red food colouring (primary colours)
  4. water
  5. paper towel


  1. Start by pouring out water to 3/4 quarters full in only 3 of the 6 jars.

2. Next add each primary colours (yellow, blue and red) to the jars of water individually, then stir.

3. Place the jars in sequence of colour next to empty, then colour next to empty.

4. Next fold 6 pieces of paper towel individually in half and then in half again. Place the folded paper towel into half of one colour and then other half into an empty jar. Make sure all pieces are submersed in half water and half empty jar. Like the image below. This part happens relatively quickly. Water the colour grow during this step is great fun and important for critical thinking and discussion with little kids.

The walking water experiment will gradually start moving coloured water into the empty jars.

5. Allow time for the colours to draw out of the walking water.

15 minutes into the walking water experiment
Walking water colour mixes
30 minutes into the experiment.

6. Allow up to 4 to 8 hours for the red, yellow and blue walking water colours to make a rainbow around the whole circle of jars. This is enough time to have equal amounts of water in each jar.

This is what our rainbow walking water experiment looks like 12 hours later.



By day two, the colours of the rainbow became more defined. I’d suggest leaving this experiment as long as you can for better colour separation.

If you would like to see more ideas for rainbow activities with kids try these!

Written by: Sarah Courtney

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