Stay-at-home science: Color by nature
Ah, spring! The sun shines a little longer every day, and we start to see the first pops of color — purple crocuses, yellow daffodils and red cardinals.
But what’s the science behind the glorious colors we see in nature? And have you ever wondered about the colors that we use in our everyday lives — to dye our clothes, paint our houses and color our dishes?
You may remember from grade school science classes that color is not a real property — the sky isn’t blue, it just appears blue. Color is a matter of how we perceive light reflected by an object. Understanding how color works brings together many fields of study — physics, neuroscience, chemistry, biology and art — and provides new areas of discovery to scientists all the time.
One interesting area for exploration is how animals see color differently than humans and each other. There are some known colors that we can’t see — ultraviolet, for instance, can be seen by spiders, bees and butterflies but not by people. Meanwhile, your pet dog or cat can only see muted blues and yellows, but no red.
Of course, people don’t all see the same either — color-blindness affects approximately 8% of men and a much smaller percentage of women. Individuals who are color blind usually don’t see red and green wavelengths in the same way as most people.
- Activity: Check out the book They All Saw a Cat by Brendan Wenzel. This picture book considers how a cat might appear from the perspective of different creatures it encounters on a walk. In addition to beautiful illustrations, the book is a good prompt for discussing how we all see the world in different ways.
How do animals and plants get their amazing colors? Animal and plant cells contain pigments that change the wavelength of reflected light by absorbing some of it. This color formation can be pretty basic — for instance, in humans our skin color typically does not change dramatically during our lives — or it can be complex, such as in animals and plants that change colors quite regularly. Some animals have specialized cells called chromatophores that help them change color to warn off predators, respond to dangers or signal changes in mood or temperature.
These cellular processes explain how a sugar maple goes from green to red in the autumn, or a chameleon changes from light green to dark blue when it gets cold. Octopus, squid and other cephalopods are masters of change, producing different colors and skin textures as needed!
So what about color in our everyday lives? Most of the color we see in our homes comes from synthetic dyes and pigments. It used to be that dyes were made from natural materials like bark, berries, leaves, roots and minerals. The color Tyrian purple was made from snails! But these days, most dyes are made in the chemistry lab and can produce huge amounts of toxic waste during the manufacturing process of goods like textiles, paper, cosmetics and foods.
- Activity: Experiment with making natural dyes from plant material. The Internet abounds with recipes and ideas — for example, use turmeric to make yellow, onion skins to make orange, beet skins to make red, purple cabbage for blue. The most vibrant colors will be from fresh plant material, not dried, but just give it a go with whatever you have in the cupboard and have fun. Once you have some great colors, you can dye paper or fabrics for craft projects.
- Activity: Create a rainbow indoors! Search for items around the house to make a life-size color wheel (see photo). Try using clean laundry from the dryer. After a fun photo shoot, the next step is a folding party! Bonus points for putting your clothes away afterwards. Count this project as a win-win.
The natural world is rich with magnificent colors — have you seen the rainbow colors of the mantis shrimp, which is also the species that sees the most color of any in the world? What about the marble berry, an African plant with an iridescent purple-blue shine that is considered one of the most intense colors in the world? And scientists recently discovered that some flying squirrels can glow a bright pink under ultraviolet light — what?! They have the unique ability to absorb light in one wavelength and emit it another, something that only a few mammals are known to do.
These exotic-seeming creatures may not be in your backyard or out your front door, but nature is also full of more subtle color variations — just bend down and observe the different shades of gray in a rock or green in a leaf. The nature artist Andy Goldsworthy builds incredible sculptures out of leaves, rocks and sticks but one of the most striking aspects of his work is how much color is revealed by simply stacking and organizing many objects that seemingly look the same.
- Activity: What colors can you see outside your front door or window? A simple activity for kids is to make a color chart with 5–6 rows and columns. Across the top, use markers or paints to fill in the colors red, blue, green, yellow/orange and purple. Then head outside — or look out your window — to see how many colors you can find. Can you spot red berries? Green moss? Orange leaves? Fill in your blank squares with the names or pictures of what you find. Discuss what you see — what color is the hardest to find? The easiest? (If you do head outdoors to do this activity, remember that you don’t want to collect anything, just observe. Leave nature where you find it.) Get creative and make a color bingo game for the whole family!
With spring arriving we’re sure to see more color all around — be on the lookout for bees, butterflies and buds to brighten your day! It’s that simple.
