Walking Rainbow Experiment +Free Printable

Can you make water walk? With just a few simple materials you can create a walking rainbow. Spark an interest and love of science with this activity. Learn about how the water moves as children notice the colors mixing with this beautiful walking rainbow experiment.

In just a few hours the water begins to “walk” and move from cup to cup and then mix to create a full rainbow. Children will love checking on their experiment throughout the day and observing the changes.

Print the free instruction sheet and worksheet to extend the learning.

This classic experiment is a fun and easy experiment to try out in any classroom or at home with kids.

walking rainbow experiment shows a pinterest pin with rainbow colored water in cups.

Walking Rainbow Experiment Materials

One of the great things about this experiment is that you only need a few household materials. You will need:

  • Red, Blue and Yellow Food Coloring
  • Paper Towel
  • 7 Clear Cups
  • Water
  • Printable Instructions and Worksheet
walking rainbow experiment shows three jars of food coloring, cups and paper towels.

If you don’t have all of the colors of food coloring, or any colors, the experiment will still work because the water will still move. However, you won’t get the color mixing affect which is what makes the experiment special.

The instruction printable is a great resource to have on hand when you present/do the activity. This way you know which cups to fill and what color to add to each cup. You can also print the worksheet for children to fill out and explain what they saw happen.

science experiment shows two printables for a walking rainbow experiment.

Walking Rainbow Experiment Steps

Add water to the first, third, fifth and seventh cup. A little more than half way is best.

Next add red food coloring to the first and seventh cups. Add yellow food coloring to the third cup and blue to the fifth cup. For best results add more yellow food coloring to help when it mixes. The red and blue food coloring can be overbearing and prevent some of the other colors from showing up well.

science shows seven cups and four with colored water.

Once you have your cups prepared, fold a piece of paper towel lengthwise and arch it from the first into the second cup. Continue this so that paper towel is arched over each cup as shown below.

rainbow experiment shows cups with colored water from a birds eye view.

That’s it! That’s all you have to do to prepare the experiment. This is also a great opportunity to ask children what they think is going to happen. Will the water change in anyway? What will the paper towel do?

Within minutes, children can observe that the paper towel begins to absorb the colored water and it begins to move up the paper towel.

color mixing for kids shows cups with colored water.

After several hours, or for best results, leave overnight, children will notice lots of things that happened!

Walking Water Experiment Explained

The experiment is complete when each of the cups have the same amount of water in them.

When children first see the experiment once the colors have mixed, there will be lots of excitement! The cups that did not originally have any water now are half full of a new color of water. Notice that the water not only ‘walked’ up the paper towel, but it also mixed with the water from the other paper towel dipped into it to create a new color.

You’ve created a beautiful rainbow!

walking rainbow experiment shows cups with all the colors of the rainbow in each.

The Science

The paper towel absorbs the water. the water travels up and over! But how? The water travels using something called capillary action. Capillary action is when a liquid can flow, even against gravity. This is similar to how water travels up the roots of a tree to get to the top of the tree and leaves.

Water molecules like to stick together and they also like to attract or stick to other porous materials, like the paper towel. As soon as one molecule, or drop, of water is absorbed to the paper towel, the others follow, like a string.

color mixing shows three cups with blue and green and yellow liquid in each.

Once colored water has moved up and over and is in the next cup, the colored water mixes with the different colored water from the other cup to create a new color.

Walking Rainbow Experiment Extension Ideas

This walking rainbow experiment is a great science experiment, but it is also a fun art activity for kids. It is a great way to show children about color mixing.

The three colors the experiment begins with, the red, yellow and blue, are called primary colors. These are the colors that all others colors are made from. When these colors mix together, the new color that is created is called a secondary color. The red and yellow mix to make the secondary color, orange.

walking rainbow experiment shows a circle of cups with rainbow colored water in each.

The red and blue mix to create purple and the blue and yellow mix to create green. In the end you’re left with a beautiful rainbow!

Another extension idea is to create two walking rainbows and test if warm water makes any difference. If you have one rainbow with cold water, and the other with warm, does the water move faster? It’s fun to test out and have children guess what will happen.

walking water rainbow shows cups with dried paper towel in each with the colors of the rainbow in each.

We left our rainbow out for several weeks because the children, and I loved looking at it. After some time all of the water evaporated and we were left with several beautifully colored paper towels.

Free Walking Rainbow Printables

This classic experiment provides children with lots of learning opportunities. Use the printables to make setting up the experiment fast and easy. Print the worksheet to have children record their learning. Click the image below to access the pdf.

free printables for a walking rainbow experiment.
Walking Rainbow Experiment Printables


Leave a Reply

Your email address will not be published. Required fields are marked *