Easy Rainbow Walking Water Science Experiment For Kids

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By In The Playroom

Today, we’re going to embark on a fantastic journey through the rainbow, with a fun water science experiment for kids. But guess what? This is no ordinary rainbow – it’s a rainbow that walks! We’re going toltake you step by step through the “Rainbow Walking Water Science Experiment.” 

This classic and easy science experiment is a great way for kids of all ages to delve into the fascinating world of science, color theory, and have a whole lot of fun while doing so!

This experiment leverages a natural phenomenon known as the process of capillary action. In this process, water molecules move up narrow spaces against the force of gravity. You might have seen this in action when a plant’s roots absorb water from the soil. Here, we’re going to mimic this effect using simple supplies – empty cups, water, food coloring, and paper towels. 

walking water rainbow science experiment

We’ll see water climb, colors mix, and a beautiful walking rainbow form, right in your kitchen or living room!

How to Make Your Own Walking Water Rainbow Science Experiment
Yield: 1

How to Make Your Own Walking Water Rainbow Science Experiment

Prep Time: 10 minutes
Active Time: 15 minutes
Additional Time: 5 minutes
Total Time: 30 minutes
Difficulty: Easy

Embark on a mesmerizing journey with the "Walking Rainbow Water Experiment". In this simple experiment, observe as water walks through paper towels, creating a captivating spectacle of a rainbow in motion.

Witness the magic as primary colors blend to form secondary colors, bringing the rainbow to life right before your eyes.

This experiment offers a vivid and educational experience that beautifully demonstrates capillary action and color theory.

Watch in awe as your everyday cups and paper towels transform into a walking water rainbow, creating a delightful and educational moment for kids of all ages.


  • Clear Plastic cups
  • Paper towels
  • Food Coloring


  • None


  1. Step 1: Grab around six clear cups and place them in a circular formation. You can use slightly more of slightly less cups if you prefer, anywhere from 5-7 cups will work well. Pour water in the 1st, 3rd, and 5th cup, leaving the 2nd, 4th, and 6th cups empty. We'll refer to these as our water cups and empty cups. It works best if you have the water cups pretty full.
  2. Step 2: Now, let's create a rainbow in our water cups. Add 5 drops of red food coloring to the 1st cup, 5 drops of yellow food coloring to the 3rd cup, and 5 drops of blue food coloring to the 5th cup. These are our primary colors.
  3. Step 3: Cut six equal size paper towels into strips. Fold each strip lengthwise, so they become narrow enough to fit into the cups but still have much excess paper towel to soak up and transport water.
  4. Step 4: Submerge one end of the paper towel strip into a water cup and the other end into the adjacent empty cup. Repeat this process for all the cups. It's important that the paper towel strip is touching the bottom of both cups.
  5. Step 5: Watch and wait. You will begin to see the colored water travel up the fibers of the paper towel thanks to adhesive forces. The absorbent paper towels, full of small fibers and tiny gaps, act as capillary tubes. In a couple of minutes, the water will "walk" to the next jar.
  6. Step 6: Over a longer time, you will see the water level in the empty cups rise, and new colors will begin to form as the primary colored water mixes. These new colors are your secondary colors.
    Congratulations, you've created your own walking water rainbow!

Did you make this project?

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Lessons and Benefits of the Walking Water Science Experiment

This experiment is much fun and more than just a pretty show of colors. As budding scientists, kids get a hands-on understanding of several scientific principles.

Understanding Capillary Action

The attractive forces between water molecules (cohesive force) and the cellulose fibers in the paper towel (adhesive force) are stronger than the forces pulling water molecules down (gravity). This is what makes water move up the paper towel strips and gives kids a live demonstration of capillary action.

Color Theory

This fun experiment introduces color mixing, transforming primary colors into secondary ones. By simply observing the process, kids learn that red and yellow make orange, yellow and blue make green, and red and blue make purple.

Scientific Method

This simple science experiment is a great way to introduce the scientific method to kids. They form a hypothesis about what will happen when the colored water climbs the paper towel, then observe and note the results, learning to  accept or reject their initial assumptions. This enhances their critical thinking skills and piques their interest in scientific exploration.


Science often requires waiting for results. The walking water experiment takes time as the water slowly seeps from one cup to the next. This process helps children develop patience as they eagerly await the formation of the rainbow.

Environmental Connections

This experiment can be a launchpad for discussions about how plants utilize a similar process to pull water from the soil up into their roots and stems. Kids learn about the amazing ways nature uses science.

Fine Motor Skills

 For younger kids, this experiment helps improve fine motor skills as they carefully pour water and place paper towels. Older kids can take on the role of leading the experiment, enhancing their organizational and leadership abilities.

The walking water rainbow science experiment offers not just an opportunity for kids to create their own rainbow at home, but also serves as a visual feast that helps illustrate key scientific principles and color theory.

It’s a fun science experiment that parents and kids can enjoy together, and it requires minimal, simple supplies, making it perfect for a rainy day, a fair project, or just an everyday adventure in learning. It encourages curiosity, instills a love for science, and ensures a great time for our little scientists.

Join us next time as we explore more easy science experiments that make learning a joyous journey, not just a destination.

Until then, keep experimenting, keep learning, and keep having fun. Remember, every budding scientist is just an experiment away from a great discovery!

More Simple Science Experiments for Kids

If you enjoyed the walking water rainbow experiment, and you’re looking for more engaging and educational science activities for your little scientists, we have a trove of simple experiments that can be done at home. These experiments not only inspire scientific curiosity but also make learning interactive and fun. Stay tuned for more exciting journeys into the fascinating world of science.

More Rainbow Activities

Our exploration of rainbows doesn’t end with the walking water rainbow experiment. For those who can’t get enough of the colorful magic, we have more rainbow-themed activities lined up. These vibrant activities will not only keep your kids entertained but also add a splash of color and creativity to their learning process. Keep an eye out for more captivating rainbow adventures!

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Anna Marikar, mum of four and seasoned blogger, has spent over a decade sharing her parenting journey and passion for kid-friendly crafts and free printables.
Her easy-to-follow craft ideas and practical parenting advice have transformed In The Playroom into a cherished resource for parents.

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