Learn how to make a rainbow like the ones you see in the sky using materials you probably have on hand.
How to Make a Rainbow
Here’s what you need:

- clear glass of water
- a piece of white paper
- masking tape
- flashlight
- (possibly will need a can or jar)
How to Make a Rainbow
- Cover the flashlight with two pieces of tape leaving a slit in the middle.
- Shine the flashlight through the glass of water onto the piece of paper.
- The rainbow should appear on the paper. {Turn off the light to see it better.}
- You may need to sit the glass on top of a can or jar of peanut butter {in my case} to raise the glass up higher.
- Play with the angle of light shining through the glass until you get a good rainbow. For me, shining the light near the top of the glass {by the rim} worked the best.
The Science Behind It
The light from the flashlight (white light) contains all the different colors of light (Red, Orange, Yellow, Green, Blue, Purple {or Indigo and Violet if you prefer}). When you shine the light through the water or onto the DVD, it refracts (bends) and splits into the different colors. This is because the different colors (wavelengths) of light behave slightly differently as they travel through the water and glass.
More Rainbow and Play Ideas
- For more flashlight fun, check out Shadow Play Science.
- Use a rainbow to learn colors in this fun toy scavenger hunt.
- Use a little science to make rainbows in milk.
Then, for even more rainbow awesomeness, check out all of the rainbow posts below.
This post was originally published on April 25, 2012. The Outlaw Mom organized a blog hop to bring you our favorite ideas for kids involving rainbows.

Enjoy the rainbows!
Linking up here.





Hey that is a great idea – my children will love that.
I don’t have a rainbow activity we have done but shall link you up on my memes page.
Pinkoddy recently posted..Thursday’s Thought – Do you tell a child they have/might have Asperger’s Syndrome?
Thanks! If you try it, you’ll have to let me know how it goes. I would love to see a picture of your rainbow.
Wonderful activity. We just watched a Magic School Bus episode about making rainbows from white light. We’ll be trying this very soon!
Miss Courtney recently posted..What My Child Is Reading: Something old, Lots of new!
So glad you liked it, Miss Courtney! If you take pictures, feel free to share them on my Facebook wall.
Love this! Going to try it today!
I would love to see a picture of your rainbow! You can post it on my Facebook wall if you want.
OOh this is fab. Was thinking about the prisms we used to have in school science to make rainbows and have been thinking how do you create rainbows without the special prisms – now I know all I need is a torch and a jam jar – can’t wait to try this with my 4 year old. Thanks for sharing. Ellie
I’d love to hear how it went for you! You may need to try a few different kinds of glass. I tried with a Mason (canning) jar and couldn’t get it to work, but a regular juice glass worked just fine.
What a cool experiment! Love all the rainbow posts in the linky, too!
maryanne @ mama smiles recently posted..Mackinac Island, Michigan – Exploring Geography
Thanks, MaryAnne! My son was creating and hunting for rainbows for days after we did this.
Lovely, thank you for sharing!
MaryLea (pink and green mama) recently posted..Poured Paint Easter Eggs!