A Color Mixing Experiment for Kids

Rainbow in a Bag: A Color Mixing Experiment


A Color Mixing Experiment for Kids

Many thanks to Kimberly Stoney who sent me this color mixing idea and recipe! It worked wonderfully. Kimberly tests and develops crafts for a children’s magazine. Doesn’t that sound like a fun job?!

We had tried mixing two different colors of tempera paint in a plastic bag after reading about Gwyn’s color mixing project on My Kids Art, but the paint was so intense that we didn’t get very good results. The orange we mixed was way too red and the purple was also way too red. Maybe we just used too much red…

But when Kimberly e-mailed me the recipe for Rainbow in a Bag, I was excited to try it.

Here’s the recipe she sent:

Rainbow in a Bag :: A Color Mixing Experiment

Color Mixing Experiment for Kids

Combine 1 cup cornstarch, 1/3-cup sugar, and 4 cups cold water in a large pot.

Heat and stir constantly. Once the mixture begins to thicken, remove it from the heat and continue to stir for another minute. Divide the mixture into 2 bowls and set aside to cool. Add a few drops of food coloring to each bowl (one red bowl and one yellow bowl for example). Put some of each color mixture into a Ziploc gallon bag (and seal with duct tape if necessary). Let the child mush and mix the two colors together. Hang in the window to let the light shine through.

My notes ::

  • I divided our mixture into three bowls for red, yellow, and blue, so that we could try mixing orange, green, and purple.
  • We used sandwich bags and didn’t need the duct tape.

Color Mixing Experiment for Kids

This recipe is easy to make (I was just starting to get over the flu when we did ours a few days ago so easy was a prerequisite), and creates a whitish base that you add food coloring too. I think the base is what helps make it effective as a color mixing project.

Color Mixing Experiment for Kids

This color mixing experiment was lots of fun—squishy and sensory! And the bags of colored gel looked great in the window with the light shining through! Kind of like stained glass.

More Color Mixing for Kids

Pin It for Later ::

A Color Mixing Experiment for Kids


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  • Reply
    March 8, 2008 at 4:59 am

    great idea! i’m trying not to use plastic bags but will have to make an exception for this…

  • Reply
    Melissa A
    March 8, 2008 at 6:46 am

    I can’t wait to try this. Also, its a great way to reuse my plastic bags (I hate to throw anything away). Thanks!

  • Reply
    March 8, 2008 at 9:06 am

    Thanks for another great idea.

  • Reply
    March 8, 2008 at 1:50 pm

    I am looking forward to trying this one, my little one is very much into colour mixing at the moment.

  • Reply
    March 10, 2008 at 5:00 am

    I’m going to try this project this week!

  • Reply
    My to do list This Place
    March 26, 2008 at 7:54 pm

    […] Rainbow in a Bag […]

  • Reply
    June 25, 2008 at 1:43 pm

    Hi there, I found your site recently and love it! I did this project with my 20-month-old son the other day and we had a lot of fun. I was wondering if you did anything with the resulting mixtures? I was thinking maybe we could fingerpaint with it, but the the dye would probably stain his fingers. Any other ideas?

  • Reply
    The Artful Parent
    June 25, 2008 at 2:19 pm

    You know, we just left the bags of color out on the windowsill for a while to squish and hold up to the light, but I think fingerpainting with it would probably work great. The texture seems right, and I don’t think it would stain his fingers. The food coloring stains fingers when full strength, but it doesn’t stain fingers when used in playdough, so I think it would be fine. Let me know how it goes! – Jean

  • Reply
    November 14, 2008 at 8:33 am

    I just discovered your site and love it. I have a 20 year background in early childhood education and have always felt the arts were explored way less than they should be in most child centred environments. I’m going to try Rainbow in a bag today with my 3 year old daughter. I am inspired by you to look into starting an art club in my neighbourhood. Thanks for an amazing blog!!

  • Reply
    Janice Tirmenstein
    December 18, 2008 at 3:52 pm

    Place the mixture in a sandwich bag so that the bag is about 1/3 full. Drop some food coloring, red, green, yellow AND blue in each bag. You can make all the colors in one bag and it really looks more like a rainbow.
    Retired 1st grade teacher.

  • Reply
    March 4, 2009 at 4:14 pm

    Just discovered this blog and this is the first project I’ve tried… Was disappointed that mine never really firmed up! I’ve since seem similar projects and the ratio of cornstarch to water was 1:1 (instead of 1:4), so maybe that is the problem? Or perhaps because I am was using raw sugar? Anyone?

  • Reply
    The Artful Parent
    March 5, 2009 at 2:05 am

    Michele, Did you stir it constantly? That really makes a difference. And I guess I’d say try it again with regular refined sugar and make sure the water is cold when it goes in the pot. I used the 1:4 cornstarch to water ratio and got the results you see in the pictures. The mixture stays pretty mushy but it does gel. I hope you have better luck with it next time! -Jean

  • Reply
    March 15, 2009 at 7:20 pm

    Jean I finally got around to trying this this weekend and it was a big hit. To anyone else thinking of trying it, I will note that at first, as I stirred over heat, I was getting little blobs of the “gelled” stuff. Looked like semi-transparent pudding! I thought I had done something wrong. But I just kept stirring, and then, like magic, it all came together, and rather quickly too.
    This is a great project to do one-on-one because all the steps leading up to it–measuring out the ingredients, watching Mom stir it, adding the food color drop by drop, and stirring the color in–were almost as much fun as squishing the colors together. I was pleased with how quickly SR picked up the primary colors concept. Today we did a second set of bags and she was telling me, unprompted, “yellow and blue make green!”

  • Reply
    Anna Clark
    April 20, 2009 at 7:29 am

    I tried this project with 20m.o., 28m.o., 3y.o., and 4.5y.o. recently. I made the base mixture and we made the primary colors and divided into 3 quart sized ziplock bags for the kids to mix and make the secondary colors. This was for fun and to reinforce primary secondary colors with the 4.5y.o. They all enjoyed the sensory experience and the 28m.o. and 3y.o. are working on color recognition. So the next day I made another batch and I gave them the white base in the ziplock with a few drops of coloring in each bag to make red, yellow blue. SO, we ended up with 6 bags total including red, yellow, blue, purple, green and orange. I taped the bags closed with clear packing tape and I’m glad i did because I could see a couple bags did leak into the tape section.
    THey were beautiful hanging on the window and they came and poked them frequently giving me an opportunity to keep working on color recognition THEN we used them for FINGERPAINTING! The mixture was wonderful for the activity and I didn’t have to worry about the youngest child occassionally tasting the mixture. I have some remaining that i refrigerated and we can try it again this week.
    This was an excellent activity for my multi-age group!
    (Note: Clean up was easy. I did get a bit of food coloring on the table when I was dropping it into the bags and it came off easily with some baking soda and a cloth.)

  • Reply
    Tot School this week Chasedbyblessingss Blog
    April 24, 2009 at 3:35 pm

    […] in a bag color mixing sensory activity as described by The Artful Parent. We created orange, purple, green through color mixing last Friday (failed to snap pics) and on […]

  • Reply
    October 14, 2009 at 4:38 pm

    Another great way to do this is with jello. It’s exciting because afterward they can eat the new colors they create.

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