Some organisms' colors come from structural color—tiny structures that distinctly scatter different colors of light, eliminating some while reinforcing others that become visible.

The color of bird feathers comes from a combination of pigments and structural color, with the latter enabling some to glow in ultraviolet light.

Violet is the rarest color in nature because it is the most energetically demanding visible light for pigments to reflect and for nanostructures to scatter.

Creating a perfect red pigment that is vivid, durable, and nontoxic is likely impossible.

Some organisms can change color by quickly revealing or hiding various pigments, as seen in octopuses, squids, and other cephalopods.

Not all colored materials can become pigments—the process of grinding materials down into smaller particles may destroy the color-producing molecules.

Starting with red, colorful objects will appear to lose their colors the deeper they are submerged because water scatters light, reducing the amount available to reflect off objects and be observed.

Organic pigments can be made in a lab or in nature—the term indicates the presence of carbon-hydrogen bonds, not their source.

The same pigments that enable photosynthesis—chlorophyll a and b—are also responsible for giving most plants their green color.

Water is naturally tinted with a slight blue, but sediments and organics can alter its color

Egg yolks and carrots have the same pigments that contribute to the yellow and orange colors of fall foliage.

Blood can be blue, green, magenta, or transparent due to differences in the oxygen-carrying respiratory pigments they contain.

Humans can distinguish about 10 million colors—a number that is limited by photopigments that only activate when exposed to specific wavelengths of light.

Color originates from the brain processing light of varying wavelengths

Some octopuses change color while they sleep, potentially in response to dreaming about hiding, hunting, or other activities that involve changing color while awake.

Fossilized pigment granules have enabled scientists to deduce the colors of long-extinct organisms, including dinosaurs.

View a gallery of plants made to shine using ultraviolet-induced visible fluorescence photography, in which organisms re-emit the ultraviolet light they are exposed to in vibrant, glowing colors.

Virtually all plants are biofluorescent because their photosynthesis is powered by chlorophyll, a pigment that glows red as a way to get rid of excess energy when exposed to ultraviolet light.

By separating light with tools such as prisms, scientists can reveal the presence and composition of celestial matter by identifying color fingerprints unique to specific elements and molecules.

Chameleons change color by altering the spacing of nanocrystals under their skin, which changes what colors of light are absorbed and reflected.

When processing light, the brain can perceive colors with no natural wavelength

The chlorophyll in plants captures energy in the form of red and blue light

Leaves have orange and yellow pigments year-round, but they are masked until the fall, when shorter days reduce the production of chlorophyll, a green pigment.

Flamingos get their pink color from pigments in their food, but they cannot be any color because their bodies cannot process every type of pigment.

Sunsets can exhibit a greater variety of colors due to a greater range of cloud heights and atmospheric composition.

Scientists can tag distinct proteins with fluorescent probes that emit different colors, allowing them to visualize multiple biochemical processes simultaneously.

Breaking down sunlight and why the sun appears yellow despite emitting green light the most

View a gallery of biofluorescent animals, which contain cells that emit various colors when exposed to ultraviolet light.

Coral reefs get their colors from zooxanthellae—photosynthetic algae that line corals' digestive tracts and provide them with sugars in exchange for a home.

View a gallery of microscopic images of butterfly wings, revealing colorful layers of scales, hairs, and metallic-looking structures.

In the 1950s, Alan Turing developed a mathematical model to explain why animals have stripes, spots, and other patterns based on differences in how quickly two interacting chemicals spread throughout a developing organism.

Some corals absorb harmful ultraviolet radiation and re-emit it as visible light, thereby protecting symbiotic algae within their tissues and providing them with energy for photosynthesis.

Biofluorescent animals—those that absorb light, such as ultraviolet rays, and re-emit other types of light, such as neon green—include some flying squirrels, scorpions, sea turtles, and platypuses.

Blacklights can illuminate certain biological materials, including blood, teeth, and fingernails, because they contain fluorophores—molecules that visibly glow immediately after exposure to higher-energy light.

Colored diamonds result from elemental impurities, structural deformities, and exposure to radiation.

The RGB color system resembles how quantum chromodynamics models quarks and the strong nuclear force—both quarks and gluons carry color charge.

Melanin and light scattering contribute to different eye colors

Bioluminescent organisms produce their own light through chemical reactions involving unstable, energetic molecules, while biofluorescent organisms almost immediately re-emit light shone on them, but at a different wavelength.

Tetrachromacy allows humans to observe 10 times the normal amount of colors

Paints are primarily made of pigments from rocks, plants, insects, or synthetic sources, combined with binding agents, solvents, and other potential additives for specific purposes.

Blood color differs across the animal kingdom, with some animals producing blood that appears green (a group of lizards in New Guinea) or blue (horseshoe crabs).

View an animation of how certain chemicals fluoresce—that is, emit visible light after having absorbed higher-energy light, such as ultraviolet radiation.

Colorizers convert Hubble's gray scale images into color composites of different wavelengths

The oldest colors in the geological record are bright pink pigments from about 1.1 billion years ago, according to researchers.

Rayleigh scattering of light gives the atmosphere its blue skies and red sunsets

Synchrotron radiation has revealed the fur color of creatures millions of years old

View examples of luciferin, the light-emitting molecule behind bioluminescence

Instead of consuming water and carbon dioxide to produce oxygen and sugar, anoxygenic photosynthesis involves alternative reactants and products.

The world's oldest known synthetic pigment—Egyptian blue—was created about 5,000 years ago.

Atmospheric composition and temperature impact the color of lightning

The outermost shell of electrons in an atom dictates how it bonds to other atoms, including those of the same element, and the properties of the materials composed of those atoms.