Gorgeous Rainbow Science and Activities

Who isn’t struck by a sense of awe at the magical site of a rainbow appearing in the sky? Kids love anything to do with rainbows, and learning all the rainbow colours. And that moment when a colorful rainbow appears in the sky is always met with squeals of delight! We’ve had a lot of fun over the years doing activities inspired by rainbow colours. It always makes for a gorgeous activity kids love. Check out this list of rainbow science experiments and activities.

Rainbow Science and Activities

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Rainbow Colours

From a very young age, children love learning about rainbow colours and the order of the colours. The first acronym I learned was ROY G BIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet), and I would proudly proclaim it to the world whenever a rainbow would appear in the sky!

Rainbows are this magical creation that can appear suddenly in the skies, and fade away just as rapidly. Children love the idea of chasing the ends of the rainbows, as if the rainbow colours hold treasures and surprises from their wildest dreams.

The Science of Rainbows

Rainbows also have some fascinating science behind them. Have you ever noticed how rainbows form when the sun pops out after it’s been raining? It’s the water molecules in the air refracting, reflecting and dispersing the sunlight that causes the rainbow to appear.

Sunlight enters the raindrop where the light bends or refracts, then as it leaves the raindrop it separates into various wavelengths. These different wavelengths produce the different colours of the rainbow. There is a great article that goes even more in to the science of rainbows here.

That’s why rainbows will only appear opposite from the sun in the sky. If you want to see a rainbow, make sure your back is towards the sun and face the rain clouds.

We live far enough North that we also get Sundogs regularly. This is a rainbow that forms as a circle around the sun, instead of the normal arch most people associate with a rainbow. Sundogs are caused by ice crystals (frozen water molecules) in the air refracting the light.

Pretty cool, eh? It’s no wonder kids find anything to do with rainbows utterly fascinating! With that in mind I gathered up some really fun, exciting and educational activities and science experiments to do with your kids that involve rainbows!

Rainbow Science

Rainbow Water Beads Science

Make a beautiful rainbow in a jar with these easy Water Beads science experiment. This Rainbow Water Beads experiment is easily scaled for classroom use or at home.

Rainbow science experiment using hydrogels also known as water beads

Magic Milk

Magic Milk is a fantastic and easy experiment that creates and explosion of colour! Simply line up your food dye following the colours of the rainbow (ROY G BIV) and watch the magic unfold!

Magic milk science fair project

Rainbow Rain

Make it rain rainbows with this stunning, yet simple, shaving cream cloud experiment. Discuss how the water cycle works and the mechanism of rain as you watch the gorgous rainbow colours fall from your clouds in a spectacular display.

Rainbow Rain Shaving Cream Cloud in a Jar Experiment


This is a beautiful experiment with the most beautiful colours. We decided to do a Starry Night inspired Skittles Experiment, but one of our first times doing it, we did the colours of the rainbow. Simply line up your Skittles around the plate in order of the colours of the rainbow. Add your water and watch your rainbow flow across the plate.

Skittles Experiment for the Science Fair inspired by Starry Night

Rainbow Bridge

This STEM activity challenges kids to build a strong and beautiful rainbow bridge out of either craft sticks, pipe cleaners or paper. A fantastic project for Spring, St. Patrick’s Day, a Viking Unit study or even a Space Study of the Milky Way. Students will love this Rainbow Bridge STEM Challenge.

Rainbow Bridge STEM Activity

Crayon Candles

I think all teachers and parents have a bucket full of broken crayons kicking around. Turn them into a beautiful candle with this Crayon Candle project.

Gorgeous Crayon Candles with STEAM lesson

Rainbow Salt Circuit

We love this activity so much we have recreated it a number of different ways, including a glowing version. But this one is so beautiful with all the colours of the rainbow and the magical way it lights the LED. Check out our Rainbow Salt Circuit.

Rainbow salt circuits are an easy circuit experiment that all ages will love

Walking Rainbow Experiment

I think everyone has done the Walking Rainbow experiment, which makes it even funnier that we completely botched it the first time! It ended up being a very beautiful lesson in how mistakes can lead to amazing discoveries. Plus, we did eventually figure out how to get our rainbow walking!

The Walking Rainbow science experiment should have been easy, but due to a mistake we discovered a fascinating capillary action and natural balance project.

Lollipop Layers

Explore density with this sweet, and gorgeous, density layers experiment using lollipops. If you don’t have lollipops in all the right colours, you can substitute hard candies. The kids loved moving the bottle around and watching those layers! Warning, this experiment smells sooooo sweet!

Layered Lollipops uses candy in a beautiful candy stem challenge

Crystal Rainbows

There is something so special and so beautiful about the way a crystal rainbow sparkles. Kids LOVE doing this simple experiment and the results are stunning.

St. Patrick's Day STEM/STEAM Activity that includes some math, engineering, science and arts. A great STEM and STEAM activity for young scientists

Erupting Rainbow rocks

These look very uninteresting, until you trigger the chemical reaction and reveal a hidden rainbow inside. Kids will gasp in surprise and joy with this brilliant and easy, erupting chemistry experiment.

Erupting Surprise Rainbow Rocks


Rainbow Soap

Create a beautiful soap that will have kids reciting all the colours of the rainbow every time they wash their hands. Soap making is an easy craft with zero waste. Check out our Rainbow Soap Recipe.

Rainbow Soap For Kids

Rainbow Bath Bombs

I love the colours in these rainbow bath bombs. Sure we could have gone more vibrant, but I think the ethereal feel of the softer colours makes it feel like we plucked a rainbow right out of the sky.

Rainbow bath bombs


Rainbow Dragon’s Egg Gummies

Have you ever made homemade gummies? It is incredibly easy to do, and the homemade ones taste amazing! It’s a little more tricky to create these layered rainbow gummies, but the results are sure to be a huge hit!

Rainbow Dragon's Egg Homemade Gummies

Rainbow Fudge

This delicious and simple rainbow fudge recipe looks stunning and tastes even better. An amazing treat to add to the table of any magical, rainbow party.

Simple rainbow fudge recipe that looks amazing, tastes delicious, and is so simple even kids can make it themselves!

Rainbow Playdough

Coloured with Kool Aid, this playdough recipe has incredibly vibrant colours and smells absolutely amazing! Older kids can help make the playdough, but all kids will love building, creating and exploring with this gorgeous playdough.

No Cook Gluten Free Kool Aid Playdough Recipe

Have fun bringing your science experiments and activities alive with the magical power of rainbows!

A tall image with a dark background features 4 test tubes at the top with red, yellow, green and blue bubbling liquids inside. Then an overlay text says Rainbow Science Experiments and Activities. Below that is a prism with rainbow colours streaming out of the top.


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