20+ Color Science Experiments

By Amy Cowen on July 21, 2022 8:00 AM

Dig into the science of color with colorful, color-changing, eye-catching science experiments!

Images of color science experiments, including ph cabbage chemistry, color mixing, starch test, iodine clock reaction, and more (individual experiments described and linked below)

23 Color Science Experiments and STEM Activities for Science Class and Science Fair

Some experiments are "colorful" because they use colored water, paints, or other materials as part of the demonstration of science concepts. The collection of student science fair projects and STEM learning resources highlighted here is "colorful" in a different way. These experiments are about the science of color and help students ask and answer science questions about chemical reactions, the physics of light, including wavelength and refraction, how colors of light mix, and more. Students can also investigate how human vision detects color and how our brains sort out what we see.

Some of the experiments highlighted below are STEM activities suitable for classroom use, demonstration, informal exploration, or family science. Activities do not have built-in support for students doing science fair projects. In cases where directions for independent student science and science fair projects are also available, these "science project" versions have been noted and linked separately.

Color Reactions

In the following "colorful" science experiments, color changes result from a molecular change during a reaction.

Color-changing Cabbage Chemistry: make an indicator solution from cabbage then explore how the color of the indicator solution changes when adding acids and bases. (Student project version)
Test Your Foods for Starch: use an iodine solution to detect whether or not a food has starch. Iodine will turn from yellow/orange to blue in the presence of starch.
Discover the Flaming Colors of Fireworks: use a flame test with different chemicals to show what colors they produce when burned. (Student project version)
Crime Scene Chemistry: Determine the Identity of an Unknown Chemical Substance: in this science project, students take on the role of forensic scientist and look for color-changing chemical reactions to help identify an unknown powder in a hypothetical crime scene scenario.
Investigate the Kinetics of the Color Changing Iodine Clock Reaction: use a modified iodine clock reaction for a green chemistry demonstration. Watch as reactants are mixed to create a solution that changes color and then experiment to determine how the reaction rate changes relative to the hydrogen peroxide concentration. (This student science project is a green chemistry variation of a classic iodine clock reaction.)
Minds of Their Own: A Chemical Reaction that Changes, then Changes Back!: in this science project, students investigate the Briggs-Rauscher (BR) reaction, an oscillating reaction in which the solution cycles from blue to yellow to clear and then repeats.

Color Separation

The following "colorful" science experiments are about the science involved in separating color molecules.

Solution Science: Candy Chromatography: use paper chromatography to uncover the colors that make up candy coatings. (Student project version)
Chromatography: Be a Color Detective: use paper chromatography to investigate the colors used in marker inks. (Student project versions: beginner, advanced)
Forensic Science: Building Your Own Tool for Identifying DNA: in this student science project, students build a gel electrophoresis chamber and use it to separate food coloring to see the individual components that make up different colors.

Color and Biotechnology

The following "colorful" science experiments involve using biotechnology to modify DNA to express pigments.

Create a Painting with Genetically Modified Bacteria: learn how bacteria can be modified with new genes that change the color of the pigment molecules. In this activity, students grow different genetically modified Escherichia coli bacteria to create a piece of art on a petri dish.
Transforming Bacteria to Make Colored Pigments: in this advanced student science project, students use bacterial transformation to explore one method of engineering DNA. (To create glowing bacteria, see the Genetically Modified Organisms: Create Glowing Bacteria! project.)

Color Mixing and the Physics of Color

The following "colorful" science experiments relate to how visible colors shift due to the mixing or separation of light.

Colored Shadows: mix red, green and blue light to investigate additive color mixing and how our eyes perceive colors. (Student project version)
How Many Colors in a Rainbow?: use a glass container of water, the sun, and sheets of white and colored paper, to make rainbows and learn about refraction.
Sunset Colors in a Glass: use a milk-water mixture and a flashlight to investigate why we see different colors in the sky at different times of the day.
Mixing Light to Make Colors: in this science project, students explore the mixing of light with separate experiments using colored filters and food coloring. (Related advanced student project)
Spinning Colors: How Do Primary Colors Combine to Make New Colors?: in this science project, students learn the difference between additive and subtractive color mixing and experiment with additive color mixing using a colored wheel attached to a spinning drill.
How Blue is Your Sports Drink?: in this chemistry project, students build and use a simple spectrophotometer to measure and compare the concentration of Blue 1 in different sports drinks.
See the Light by Making a Cell Phone Spectrophotometer: use a cell phone to build a simple spectrophotometer and use it to investigate how visible light is absorbed by differently colored solutions.

Color and Plant Science

These "colorful" plant science student projects explore the importance of color in plant biology and how color-sensing technologies can be used to improve agricultural processes.

Find the Hidden Colors of Leaves: investigate the pigments in leaves and why different colors show up in cool weather than in warm weather. To find out what colors might be hiding in a leaf, students use paper chromatrography to separate plant pigments. (Related student projects about leaves and flowers)
Is It Ripe Yet? Build a Circuit to Detect Ripe Produce: in this electronics project, students build a sensor-based circuit that can help tell when produce is ripe and ready to pick based on the color of the fruit or vegetable.

Color and Human Perception

These "colorful" experiments help students investigate how we detect and perceive color.

Color Taste Test—Do You Taste with Your Eyes?: is color related to how people respond to a food or drink? Put the question to a taste test! (Student project version)
Seeing Science: Exploring Perception with the Stroop Effect: explore the Stroop effect, interference, and how the brain works to make sense of what we see and how we read. (Intermediate and advanced student projects)
Afterimages: The Colorful Tricks Eyes Play: when you stare at an object for several seconds and then look away, you may see an afterimage, a similar image in a different color. These images are not really there, but this activity explains how they are related to human vision and our perception of color. (Student project version)