Color Science - Catching a Rainbow in a Bottle

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Ever wonder how to find the end of the rainbow and that elusive pot of gold? Well look no further, because you can build your own rainbow and capture it in a container using science!

Color Science - Catching a Rainbow in a Bottle


  • 1 clear container, glass, or jar (we recommend an empty tennis ball can)WaterGelCrytals
  • Food coloring
  • Water gel crystals (can be ordered online)
  • Water
  • Three 7 oz cups


Step 1 - Separate 3 cups and add one tablespoon of Water Gel crystals to each cup.Separate 3 cups and add Water Gel Crystals to each cup

Step 2- Add about 5 oz of water to each cup

Step 3- Add 5-10 drops of Yellow food coloring to one cup, Red to another, and Blue to the 3rd cup

Step 4- Allow 30-45 minutes for water to absorb into the gel crystals

Step 5- Okay, this is where you have to do some real thinking! You need to determine how to add the colors (blue, red, and yellow) to the container in order to make a rainbow appear! Do you remember the colors of the rainbow? Remember, ROYGBIV! How should you layer the colors?

Step 6- Once all the colors are added to the tennis ball container allow the colors to meld together and enjoy your new rainbow in a bottle!


Results and follow-up:Add food coloring to each cup

What was the order of the colors?

What happened after you put the colors in? Did they stay separate or merge together?

Did you need to make a green cup? Why or why not?

You are now one step closer to finding that pot of gold! Now, where can we find some gold? Hmmm...


Determine which order to add the colors in to make a rainbow Rainbow in a bottle