Colors from Nature: Make a Simple Dye

Students observe how teacher-prepared plant materials color water, classify the resulting dyes, and compare natural color-making today with practices from the past.

Color Sources Then and Now

Long ago, people could not buy every color in a bottle. They often made colors from plants and other materials found in nature. For example, they could use yellow onion skins to make a yellow or golden dye. They used dyes to color cloth, yarn, baskets, and other useful objects. People still make some dyes from nature today, but many dyes are now made in factories and sold in stores. Look at a piece of naturally dyed cloth and a piece colored with modern fabric dye. What looks the same? What may be different? Talk with a partner and take turns sharing ideas. Both past and present dyes add color, but the materials and tools people use may be different.

Observe the Plant Materials

Scientists begin by observing carefully. Your teacher will show safe, prepared plant materials, such as red cabbage pieces, yellow onion skins, and spinach leaves. Use your eyes to notice each material's color, shape, size, and texture. Do not taste or put any material in your mouth. You might say, “The cabbage is purple and smooth,” or “The onion skin is thin, dry, and golden.” Compare two materials with a partner. How are they alike? How are they different? The plant's starting color is an observable property, which means it can be noticed with the senses. Place or point to each sample in a color group, such as purple, yellow, or green. Count how many plant samples are in each group.

Predict the Dye Colors

A prediction is what you think may happen. Before the dye test, look at each plant material and predict the color it may give to water. The result may look like the plant, or it may look different. For example, you might predict that purple cabbage will make purple water. Choose a color card or draw a colored circle beside each plant sample. Then explain your thinking to a partner: “I predict yellow onion skins will make yellow water because the skins look yellow.” Listen while your partner shares, and ask a question if you want to know more. Predictions do not have to be correct. They help scientists record their ideas before a test. Count the predictions for each color, and identify which predicted color has the most or the fewest votes.

Conduct a Teacher-Guided Dye Test

Now the class will test the predictions. The teacher places equal amounts of prepared plant material into separate clear, heat-safe cups and adds the same amount of warm water to each cup. Only the teacher handles warm water and moves the cups. Students watch from a safe distance and never taste the materials or dye water. The teacher gently stirs each cup with a separate spoon and waits the same amount of time. Keeping the water amount and waiting time the same makes the comparison fair. Watch for color moving from the plant material into the water. For example, red cabbage may turn the water purple or blue-purple. Describe what you notice at the beginning and after waiting. The class can record each result with a colored drawing or a color word.

Classify and Share the Results

After the cups are cool and safe to view, study the dye colors. Classify means to put things into groups by a shared property. Sort picture cards of the dye samples into color groups, such as purple, yellow, green, or little color. Count the samples in each group and tell how many there are. For example, if the cabbage sample is purple and two other samples are yellow, the class has one purple dye and two yellow dyes. Compare the results with the predictions. Which predictions matched? Which results were surprising? Take turns speaking and listening as the class makes a results chart. Finally, connect the investigation to history. People in the past observed and tested natural materials to make useful colors. People today can still make natural dyes, although store-bought dyes are also common.