Easy Science Experiments for Kids With Food Coloring: 5 Colorful Ideas

A few drops of food coloring can turn an ordinary kitchen into a laboratory. Colors spread, mix and travel in ways children can watch happening, which makes them perfect for a first look at how liquids behave. These easy science experiments for kids with food coloring use items most homes already have, take little setup, and each one comes with a simple explanation you can share.

Before you start: set up like a scientist

• Cover the table with a tray, baking sheet or plastic tablecloth. Food coloring stains.
• Use white or clear containers so colors show clearly.
• Ask for predictions. Before each step say, “What do you think will happen?” Even a wrong guess is good science.
• Talk about what you see. Words like spread, mix, sink and float build vocabulary as well as understanding.
• Try it again with one change. Warm water instead of cold, or a different color, and compare.

1. Walking water (ages 3 and up)

You need: 6 clear cups or jars, paper towels, water, red, yellow and blue food coloring.

Steps:

1. Line up the cups in a circle and fill every other cup about three-quarters full with water.
2. Add red to the first full cup, yellow to the next, and blue to the third. Leave the empty cups between them.
3. Fold a paper towel lengthwise into a strip and place one end in a full cup and the other in the empty cup beside it. Repeat around the circle so every empty cup is connected to two colored cups.
4. Watch over the next 15 to 30 minutes as the color crawls up the paper and drips into the empty cups.

What is happening: Paper towels are made of tiny fibers with gaps between them. Water is drawn into those gaps and climbs the paper, a process called capillary action. When two colors reach the same empty cup, they mix, so you finish with orange, green and purple.

2. Rainbow milk (ages 4 and up)

You need: a shallow plate or dish, whole milk, food coloring, dish soap, cotton swabs.

Steps:

1. Pour enough milk into the plate to cover the bottom.
2. Add several drops of different colors, spaced apart, without stirring.
3. Dip a cotton swab in dish soap and touch it to the middle of the milk. Hold it there for a few seconds.
4. Watch the colors burst and swirl. Try touching it in different places.

What is happening: Milk contains fat, and dish soap changes how the surface of the milk holds together. As soap spreads through the milk it pushes the fat, and the colors floating in it, around. That movement makes the swirls. Whole milk usually works best because it has more fat.

3. Ice-and-salt painting (ages 3 and up)

You need: a block of ice (freeze water in a bowl or container overnight), a tray, table salt, food coloring or watercolors, and small droppers or spoons.

Steps:

1. Place the ice in a tray.
2. Sprinkle salt over the top.
3. Drop or paint colors onto the ice and watch them run into the little channels the salt makes.

What is happening: Salt lowers the temperature at which water freezes, so it melts the ice where it touches it. The melting carves tiny grooves, and the colored liquid flows along them. Ask your child to feel the ice before and after; how has it changed?

4. The color-changing flower (ages 5 and up)

You need: a white flower (a carnation works well) or a stalk of celery with leaves, a tall glass, water, plenty of food coloring.

Steps:

1. Fill the glass with water and add a generous amount of food coloring.
2. Cut the very end off the stem or celery and stand it in the glass.
3. Check every hour and take a photo. Color appears in the petals or leaves after several hours, and more after a day.
4. For a rainbow effect, split a carnation’s stem lengthways and put each half in a different color.

What is happening: Plants draw water up through narrow tubes in their stems to reach the leaves and petals. The colored water travels the same route, so the color shows where the water has been. This is a slow experiment that teaches patience, a nice change from instant results.

5. Colorful oil-and-water jar (ages 4 and up)

You need: a clear jar or glass, water, cooking oil, food coloring, a spoon.

Steps:

1. Fill a jar about one third with water and pour cooking oil on top. Notice how they stay separate.
2. Add a few drops of food coloring. They will sit on the oil at first.
3. Gently stir the top layer with a spoon or wait, and watch drops sink through the oil and then spread into the water.

What is happening: Oil and water don’t mix, and oil floats because it is lighter than water. Food coloring is water-based, so the drops are heavier than the oil, sink through it, and then dissolve into the water below.

Ask questions like a scientist

Between steps, try questions that don’t have a single right answer:

• What do you notice?
• What do you think will happen if we add more?
• What would happen if we used warm water instead?
• Why do you think the colors stayed apart here?
• How could we test that?

Writing or drawing predictions and results in a “science notebook” turns a fun afternoon into a habit of observing and recording.

Cleaning up and keeping the learning going

Let children help wipe the tray and rinse cups, and pour used liquid down the sink rather than onto grass or soil. Because some of these experiments take time — the flower needs hours — it helps to have quiet activities on hand for the waiting. A printable like The Ultimate Kids’ Activity Book — 25 Screen-Free Games & Puzzles is designed for ages 4 to 8 and fits nicely into those gaps.

For more ideas, see our guide to science experiments for kids by age, our easy STEM activities using household items, and the classic baking soda and vinegar volcano.