Rainbow Science Experiments

This collection of rainbow science experiments is perfect for exploring colors. Use rainbows to introduce other science concepts as well.

What is a Rainbow?

A rainbow is made by separating white light into the colors of the visible spectrum. This can be done with a prism or through water. A rainbow forms in the sky when sunlight passes through water droplets in the air.

Typically we name 6 colors of the rainbow – red, orange, yellow, green, blue, and violet (purple). A rainbow of visible light is truly a spectrum – that means it’s a range of colors that gradually changes from red to violet. Sometimes you’ll see people mention cyan (a color between green and blue) or indigo (a color that’s the border between blue and violet). To be really specific, we use a number (the wavelength) to talk about the color.

Rainbow Science Experiments

How to Make a Rainbow – Make your own rainbow with a flashlight, water glass, and paper.

Layering Liquids Density Experiment – Make colorful layers of fruit juice using different concentrations of sugar.

Rainbow Foam Eggs – Turn a classic science experiment with yeast and hydrogen peroxide into a colorful sensory experience.

Rainbow Soda Geysers with Ada Twist – Make soda geysers using different colors of soda. Do they all work as well?

Rainbows in Milk – The classic magic milk experiment using soap and food coloring is a fun way to make moving rainbows.

Rainbow Texture Explorations – This is a fabulous sensory science activity that works on making observations and learning colors.

Fizzy Color Mixing Experiment – Add a rainbow of color to classic baking soda and vinegar science.

Prism Exploration – Use a prism to create and observe rainbows. Buggy and Buddy shows us how.

Walking Water Experiment – Coffee Cups and Crayons teaches us about capillary action and color mixing with this rainbowtastic activity.

How to Dye Rainbow Flowers – This activity from hello, Wonderful also uses capillary action to dye flowers. Use this idea to talk about transpiration in plants.

Make a Skittles Rainbow – This colorful science idea from Science Sparks uses water and skittles or any candy coated treats really.

Rainbow Water Xylophone – Mama.Papa.Bubba shares directions for making music with colored water.

Rainbow Spin Mixing – This STEAM activity from Babble Dabble Do combines science and art to learn about physics and color theory.

More Rainbow Activities

Color Sorting Fine Motor Activity Inspired by The Hidden Rainbow – Move the colored drops of water into their matching buckets. This one is great for observing the properties of water, too.

Find the Unicorn Rainbow Sensory Bin – Can you find the unicorn hiding among the rainbows and dragons? See the supplies we used plus all of the other rainbow inspired learning ideas from the Virtual Book Club for Kids.

Learn Colors with Ramps and Car Rainbows – I set up this car activity to help my toddler learn colors. Launch the cars down the ramp to create a car rainbow.

Rainbow Dot Art – Make a giant rainbow on sticky paper. It’s great for fine motor skills and makes a cool piece of art.

Make Rainbow Dot Art with M&M’s – This post was sponsored by M&M’s Crispy, but you can use regular M&M’s or Skittles. (M&M’s don’t have purple, so you can substitute brown. Skittles don’t have blue. Unless you order them specially.)

15 Rainbow Scavenger Hunts – If you love rainbows and you love scavenger hunts, then you will love this collection of ideas.

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This post was originally published on March 5, 2021.