Rainbow Color Mixing Science Experiment
Mix primary colored water to discover secondary colors — red + yellow = orange, blue + yellow = green. A visual chemistry lesson that's vibrant and hands-on.
What You'll Need
- 16 clear glasses or jars
- 2Water
- 3Red, yellow, and blue food coloring
- 4Spoons for stirring
- 5Paper towels for cleanup
- 6Paper for recording predictions
What You'll Need
6 clear glasses or jars
Water
Red, yellow, and blue food coloring
Spoons for stirring
Paper towels for spills
Paper for recording predictions and results
How to Play
Fill 3 glasses with water. Add red, yellow, and blue food coloring — one per glass.
Set 3 empty glasses between them.
"What happens if we mix red and yellow?" Record predictions.
Pour and mix: "Orange! Red and yellow make orange!"
Blue + yellow: "Green!" Red + blue: "Purple!"
Mix all three: "What color?" (Brown/gray.) "Not every mix makes a pretty color!"
Try different ratios: more red than yellow, more blue than red. How does it change?
The Science Behind It
Primary colors (red, yellow, blue) can't be made by mixing other colors, but they combine to create secondary colors (orange, green, purple). This is subtractive color mixing — each color absorbs (subtracts) certain wavelengths of light. When you mix all three primaries, most wavelengths are absorbed, producing a dark, muddy color. Your child is learning color theory through direct experimentation.
Tips
Clear glasses show the colors best. Plastic is safer than glass with younger children.
Use plenty of food coloring for vivid results. Faint tints are less impressive.
Record predictions before mixing. The predict-test-observe cycle is the scientific method in action.
Try the walking water version: place empty glasses between colored ones and connect with paper towel bridges. Water climbs the towels and mixes in the empty glasses overnight.
Discuss where color mixing appears in real life: painting, printing, sunsets, TV screens.
Age Adaptation Tips
School-age kids can take more ownership. Let them lead the activity, experiment with variations, and explain what they learned.
Frequently Asked Questions
How long does this activity take?
This activity takes about 20 min, with 5 min of preparation time beforehand.
What materials do I need?
You'll need: 6 clear glasses or jars, water, red, yellow, and blue food coloring, spoons for stirring, paper towels for cleanup, and 1 more item.
What age is this activity for?
This activity is designed for 5-8 years. You can adapt it for younger or older children by adjusting the complexity.
Can this be done indoors?
This activity is designed for indoor play, making it perfect for rainy days or when you're staying inside.
How difficult is this activity?
This is an easy activity that requires minimal setup and supervision. Great for busy days or when you need something quick.
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